KENTUCKY  GEOLOGICAL  SURVEY,  J.  R.   PROCTER,  DIRECTOR. 


Kentucky  Fossil  Shells 


OF  THE 


oi  Kentucky 


BY  HENRY  jN ETTELROTH,  C.  E. 


FRANKFORT,  KENTUCKY 

ELECTROTYPED  AND  PRINTED  BY  E.  POLK  JOHNSON,  PUBLIC  PRINTER  AND  BINDER  - 

1889. 


KENTUCKY  GEOLOGICAL  SURVEY,  J.  R.   PROCTER,  DIRECTOR. 


Kentucky  Fossil  Shells 


A  MONOGRAPH  OF  THE  FOSSIL  SHELLS 


NTUCKY  GEOLOGICAL  SURVEY  and  STATE  MUSEUM, 

FRANKFORT,    KY.,    U.    6.    A. 

HH  THE  COMPLIMENTS  OF 

JOHN    R.   PROCTER, 

DII5ECTOIS. 

1    '  J 


BY  HENRY  NETTELROTH,  C  E. 


FRANKFORT,  KENTUCKY 

ELECTRQTYPED  AND  PRINTED  BY  E.  POLK  JOHNSON,  PUBLIC  PRINTER  AND  BINDER 

1880. 


KENTUCKY  GEOLOGICAL  SURVEY,  J.  R.   PROCTER,  DIRECTOR. 


Kentucky  Fossil  Shells 


A  MONOGRAPH  OF  THE  FOSSIL  SHELLS 


OF  THE 


Silurian  mid  levonioii  flocks  of  hntuGky 

I  L        L  V  V  hJ 


V 


BY  HENRY  NETTELROTH,  C  E. 


FRANKFORT,  KENTUCKY 

ELECTROTYPED  AND  PRINTED  BY  E.  POLK  JOHNSON,  PUBLIC  PRINTER  AND  BINDER 

1889. 


COPYRIGHTED    BY    KENTUCKY    GEOLOGICAL   SURVEY,  1889. 


K4 


TABLE  OF  CONTENTS. 


PAGE. 

Letter  from  the  Author. 3-4 

A  Short  Sketch  of   Geology 5-27 

Description  of  Genera  and  Species 28-230 

Index  to  Genera  and  Species  described 231  239 

Index  to  Species  described 240-245 

Plates  and   Explanatory  Text..  I-XXXYI 


M65064S 


LETTER  FROM  THE  AUTHOR. 


MR.  JOHN  R.  PROCTER, 

Director  Kentucky  Geological  Survey : 

DEAR  SIR:  The  work  of  describing  the  fossil  shells,  or  Mollusca,  from  the 
Falls  of  the  Ohio,  which  you  kindly  assigned  to  me  some  years  ago,  has, 
unfortunately,  been  delayed  by  severe  illness  of  several  years'  duration.  It 
was  only  during  the  past  winter  that  I  regained  sufficient  strength  to  complete 
it.  This  monograph  contains  about  two  hundred  and  twenty  species,  forty- 
three  of  which  are  new,  and  originally  described  by  me.  The  descriptions 
and  illustrations  of  the  balance  are  scattered  over  many  different  State 
Reports,  Monographs  and  Periodicals,  accessible  to  only  a  few  persons  in 
Kentucky,  and,  for  this  reason,  it  was  necessary  either  to  copy  those  figures 
and  descriptions,  or  to  reproduce  them  from  our  own  material.  All  of  our 
illustrations  are  original,  with  the  exception  of  three  or  four,  which  are 
copied  from  Prof.  Hall's  27th  Regents'  Report.  The  drawing  and  engraving 
was  done  by  Mr.  Chas.  Starck,  of  the  Louisville  Lithographing  Co.,  who 
deserves  great  credit  for  the  pains  taken  and  the  skill  shown  in  the  execution 
of  this  work.  Of  the  original  descriptions  of  known  species,  I  copied  some 
entirely.  Coming,  as  they  were,  from  the  skillful  pen  of  Prof.  Hall,  it  was 
impossible  to  improve  them.  Others  I  have  remodeled,  and  some  set  aside 
and  replaced  by  new  ones.  In  many  cases,  the  descriptions  were  made  from 
single,  not  well  preserved,  specimens,  which  rarely  showed  the  true  characters 
of  the  shells  in  their  original  condition,  and,  therefore,  led  to  errors  in  the 
descriptions.  The  large  and  excellent  material  now  found  in  about  a  dozen 
collections  here  in  the  Falls  Cities,  while  enabling  me  to  correct  those  mistakes, 
has  also  compelled  me  to  change  descriptions  coming  from  far  superior  palae- 
ontologists. The  larger  number  of  our  fossil  shells  were,  heretofore,  described 
and  figured  by  Prof.  James  Hall,  of  Albany,  New  York,  in  his  numerous 
reports  and  pamphlets,  most  all  of  which  he  presented  to  me,  with  the  kind 
permission  to  make  the  broadest  use  of  his  illustrations  and  descriptions.  For 
such  exceptional  generosity  I  can  thank  him  only  by  this  public  acknowledg- 
ment. The  material  used  in  the  preparation  of  this  monograph  belongs  partly 
to  my  own  cabinet,  and  partly  to  the  collections  of  the  following  gentlemen : 


4  LETTER    FROM    THE    AUTHOR. 

Major  Wm.  J.  Davis,  Profs.  Wm.  J.  McConathy  and  J.  T.  Gaines  and  Dr. 
James  Knapp,  of  Louisville,  Ky.,  Prof.  A.  C.  Goodwin,  of  Charlestown,  Messrs. 
Orlando  Hobbs,  Henry  Peters  and  Mr.  Fogg,  of  Jeffersonville,  Indiana.  These 
gentlemen  have  rendered  me  all  the  assistance  I  desired  or  needed,  for  which 
I  here  express  my  thanks.  To  Major  Wm.  J.  Davis,  the  author  of  "  Ken- 
tucky Fossil  Corals,"  I  am  especially  indebted  for  much  valuable  information 
given  me,  while  on  our  numerous  collecting  trips,  and  during  the  preparation 
of  this  work.  It  has  pained  me  to  see  the  valuable  collection  of  the  late  Dr. 
James  Knapp,  from  which  Prof.  Hall  received  most  of  his  Ohio  Falls  speci- 
mens, leave  our  State.  Though  in  corals  it  was  greatly  inferior  to  the  cabinet 
of  Major  Wm.  J.  Davis,  and  in  shells  not  equal  to  my  own,  it  contained  some 
very  rare  specimens  which  it  may  be  impossible  to  replace. 

Our  shells  have  generally  retained  their  original  form,  not  having  suifered 
from  compression  or  distortion,  as  is  the  case  with  so  many  fossils  from  other 
localities,  and  their  silicification  has  prevented  all  wear  and  rubbing  after  sepa- 
ration from  their  matrix,  while,  on  the  other  hand,  their  changing  into  horn- 
stone  has,  in  many  instances,  obliterated  the  original  fine  surface-markings,  for 
the  study  and  description  of  which  we  have  to  acquire  material  from  other 
localities. 

The  descriptions  of  fossils  I  have  prefaced  by  a  short  article  on  geology  and 
palaeontology  in  general,  containing  information  indispensable  to  any  one  who 
wishes  to  gain  an  understanding  of  the  fossil  remains  of  the  fauna  and  flora 
of  former  ages.  In  preparing  said  article,  I  have  made  extensive  use  of  the 
works  of  Dana,  Lyell  and  others. 

Hoping  that  this  monograph  will  meet  with  your  approval,  and  that  it  may 
be  of  service  to  the  students  of  geology,  in  spite  of  its  many  shortcomings, 
which,  knowing  your  kind  disposition,  I  feel  assured  you  will  overlook  or 
excuse,  I  express  here  to  you,  dear  sir,  my  many  thanks  for  your  kind  con- 
sideration and  indulgence,  and  remain 

Very  respectfully,  your  obedient  servant, 

HENRY  NETTELROTH. 

LOUISVILLE,  1887. 


FOSSIL   SHELLS 


OF  THE 


SILURIAN  AND  DEVONIAN  ROCKS. 


BY 


A  SHORT  SKETCH  OF  GEOLOGY. 


A  SKETCH  OF  GEOLOGY. 


The  name  "Geology"  is  derived  from  the  Greek  words  "ge,"  the  earth,  and 
"logos,"  a  discourse,  thus  indicating  a  science  of  the  earth,  a  science  investi- 
gating the  different  materials  of  which  the  earth  is  composed,  and  also  the 
manner  in  which  these  materials  are  arranged.  Geology  gives  us,  also,  the 
history  of  our  planet  from  its  beginning  to  the  present  time — examining  all 
the  processes  through  which  the  earth  has  passed,  from  its  original  gaseous 
condition  until  it  acquired  its  present  form  and  structure.  It  furthermore 
enables  us  to  obtain  extensive  and  valuable  information  about  the  animal  and 
vegetable  life  which  covered  our  globe  during  bygone  ages. 

Geology  is  a  science  of  comparatively  recent  date,  though  we  find  some  geo- 
logical knowledge  among  the  ancient  Romans  and  Greeks,  and  in  the  writings 
of  the  middle  age.  All  that  knowledge,  however,  amounted  only  to  a  few 
isolated  speculations,  nearly  always  based  upon  erroneous  suppositions,  and 
never  resulting  in  the  establishment  of  a  regular  system.  Geology  as  a  science 
was  originated  during  the  last  century,  but  received  its  main  development  dur- 
ing the  present  one.  In  spite  of  its  short  existence,  it  has  outgrown  many  of 
its  sister  sciences,  and  ranks  to-day  among  the  most  important  ones  at  the  head 
of  the  scale.  Its  founders  and  chief  promoters  are  mainly  found  among  the 
English,  German  and  French  savants,  and  during  the  present  century  our  own 
country  has  contributed  its  full  share  to  its  advancement.  The  names  of  Lyell 
and  Murchison,  of  Leopold  von  Buch  and  Goldfuss,  of  Cuvier  and  Verneuil, 
and  of  our  own  eminent  geologist,  Professor  James  Hall,  of  New  York,  and 
many  others,  will  be  known  to  the  students  of  this  noble  science  through- 
out the  coming  ages. 

Geology  has  for  its  territory  the  whole  earth,  as  far  as  the  same  is  accessible 
to  its  investigations.  These  are  not  confined  to  the  surface,  but  penetrate  as 
deep  into  the  interior  as  artificial  excavations  for  mines  and  artesian  wells 
allow.  Still  greater  and  better  opportunities  than  these  artificial  openings, 
which  are  limited  in  numbers  and  dimensions,  are  offered  the  geologist,  for  his 
researches,  by  the  peculiar  figuration  of  our  planet's  surface,  where  deep 
valleys  alternate  with  high  mountains,  and  where  the  strata  are  bent  to  such  a 
degree  that  we  find  them  at  one  place  deep  below  the  surface,  whilst  at  a  dis- 
tance of  a  few  miles  the  very  same  layers  may  be  outcropping  at  the  slope  of 
a  hill,  or  may  even  form  the  surface  rocks  of  extensive  districts. 


6  PALEONTOLOGY    OF    KENTUCKY. 

Vast  as  the  geological  field  appears,  and  in  reality  is,  it,  nevertheless,  forms 
only  a  small  portion  of  the  whole  contents  of  our  globe.  The  deepest  excava- 
tions rarely  extend  to  a  depth  of  2,000  feet  below  the  level  of  the  sea,  though 
their  absolute  depth  may  be  greatly  in  excess  of  this,  inasmuch  as  most  of 
them  ar<§  in  mountainous  regions.  The  bending  of  the  strata  very  often  gives 
us  an  insight  into  greater  depths,  but  even  this  amounts  only  to  a  few  miles, 
and  forms  only  a  small  portion  of  the  earth's  radius.  Beyond  these  depths 
geology  is  barred,  as  far  as  actual  observations  are  concerned,  but  its  inquiries 
may  penetrate  deeper ;  it  may  speculate  about  the  nature  and  condition  of  the 
earth's  interior.  About  this  matter  different  theories  have  been  advanced,  but 
as  all  of  them  are  based  on  mere  speculation,  none  have  met  with  a  general 
acceptance  by  the  scientific  world.  Whether  the  center  of  our  globe  is  solid 
or  fluid,  whether  it  is  a  vacuum  or  filled  with  compressed  air,  we  are  unable 
to  decide  with  certainty.  Some  facts  speak  for  a  solid  and  others  for  a  fluid 
center,  and  still  others  can  not  be  accounted  for  by  either  condition. 

Some  European  scientists,  like  Leslie  and  Halley,  consider  the  earth  a  hollow 
sphere,  which,  according  to  Leslie,  was  filled  with  imponderable  material,  pos- 
sessing an  enormous  repulsive  force.  These  philosophic  speculations  of  savants 
were  taken  up  by  Captain  Symmes,  of  Kentucky,  who,  by  adding  his  own 
fantastic  dreams,  enlarged  them  to  the  so-called  "Symmes'  Theory."  Symmes 
insists  that  the  interior  of  our  globe  is  not  only  hollow,  but  that  it  is  also 
inhabited  by  animals  and  plants ;  that  it  possesses  a  very  mild  climate,  and  is 
illuminated  by  two  planets,  which  he  calls  Pluto  and  Proserpina.  He  felt 
so  convinced  of  the  existence  of  his  subterranean  country,  that  he  repeat- 
edly extended  private  and  public  invitations  to  Alexander  von  Humboldt,  Sir 
Humphrey  Davy,  and  other  celebrated  scientists  of  this  country,  and  of  the 
old  world,  to  accompany  "him  on  his  intended  subterranean  expedition. 

ROCKS. 

The  solid  portion  of  the  earth  is  composed  of  different  materials  or  rocks. 
The  term  "rock,"  as  commonly  understood,  signifies  a  hard  and  stony  mass, 
such  as  granite,  quartz  or  limestone,  but  in  its  geological  meaning,  it  embraces 
all  solid  constituents  of  our  globe,  the  hard  and  stony,  as  well  as  the  soft  and 
incoherent  matter ;  thus,  loose  sand  and  soft  clay  are  just  as  well  included  in 
that  term  as  basalt  and  quarrystone.  Before  geology  enlightened  the  people, 
it  was  the  general  belief  that  all  the  rocks,  with  their  present  form  and  arrange- 
ment, were  thus  created.  This  belief,  though  still  adhered  to  by  the  ignorant 
masses,  and  by  bigots,  has  disappeared  from  the  minds  of  all  who  ever  came 
under  the  influence  of  geological  reasoning.  Geology  informs  us,  that  all  the 
rocks  in  their  present  structure,  composition  and  arrangement,  are  the  pro- 
ducts and  results  of  many  different  conditions  under  which  our  earth  existed, 


A    SKETCH    OF    GEOLOGY.  7 

and  of  many  different  processes  through  which  it  has  passed  during  the  many 
ages  of  its  existence.  By  whatever  influences  the  rocks  may  have  received 
their  present  characters,  they  received  their  original  form  and  structure  by  the 
agency  of  fire.  All  the  rocks,  without  exception,  passed,  in  the  beginning, 
through  a  molten  condition,  out  of  which,  by  subsequent  cooling,  they  re- 
ceived their  first  form  as  solids.  But  in  the  course  of  time  another  agent 
appeared  and  changed  many  of  the  existing  forms.  Water,  the  powerful 
opponent  of  fire,  went  into  action,  and  by  its  chemical,  as  well  as  mechanical 
influence,  dissolved  a  large  portion  of  the  fire-produced  formations,  and  carried 
them  to  distant  localities,  where,  under  favorable  conditions,  they  were  de- 
posited as  sediments,  forming  those  rocks  which  are  mainly  characterized  by 
their  arrangement  into  strata  or  layers.  Again,  we  find  many  of  these  sedi- 
ment-formations have  been  subjected  to  the  influence  of  heat,  by  which  they 
lost  some  of  their  former  characteristics.  Their  crystallization,  and  the  total 
absence  of  organic  remains,  prove  the  action  of  heat,  while,  on  the  other 
hand,  their  stratification,  which  is  generally  retained,  testifies  to  their  sedi- 
mentary origin.  Thus  we  will  notice  a  natural  division  of  all  the  rocks  into 
the  following  three  classes : 

1.  Rocks  originally  formed  by  fire  and  not  afterwards  changed,  the  igneous 
rocks. 

2.  Rocks    formed    in  water    by  sediments,    the    stratified    or    sedimentary 
rocks. 

3.  Rocks  originally  formed  as  sedimentary  deposits,  but  afterwards  changed 
by  heat,  without  losing  their  stratification,  called  metamorphic  rocks. 

The  igneous  rocks  are  generally  subdivided  into  volcanic  and  plutonic  rocks. 
Their  difference  is  caused  by  the  condition  under  which  the  cooling  of  the 
molten  masses  took  place.  In  the  volcanic  rocks,  the  molten  matter  appeared 
either  on  the  surface  of  the  earth,  or  at  least  very  near  to  the  same,  where  the 
cooling  was  rapid,  and  where  the  forming  rocks  were  not  subjected  to  the 
heavy  pressure  of  the  superimposed  strata. 

The  plutonic  rocks  resulted  from  greatly  different  conditions.  Here  the 
molten  masses  did  not  penetrate  the  surface  strata,  but  remained  deep  in  the 
interior  of  the  earth,  or  at  least  at  the  bottom  of  deep  oceans,  where  the  cool- 
ing process  was  retarded,  and  where  the  new  formations  were  compressed  by 
the  weight  of  the  overlying  layers. 

In  the  column  of  strata  we  generally  find  the  plutonic  rock  at  the  bottom. 
Next  above  come  the  metamorphic  formations,  which  are  superimposed  by 
the  sedimentary  and  volcanic  rocks.  This  arrangement  led  the  earlier  geolo- 
gists to  the  belief  that  the  plutonic  and  metamorphic  rocks  were  older  than  the 
others,  consequently,  they  called  the  lower  primary  formations,  and  the  upper 
the  secondary  formations.  The  older  school  of  geologists  adhered  to  the 


8  PALJEONTOLOGY    OF    KENTUCKY. 

so-called  neptimian  theory,  according  to  which  all  the  rocks,  with  the  only 
exception  of  the  volcanic  lava  formations,  were  considered  as  produced  by 
water,  or  to  be  of  aqueous  origin.  If  this  theory  had  proved  correct,  the  views 
of  the  old  school  about  the  comparative  age  of  the  different  rocks  would  be 
sustained.  But  progress  in  geological  science  has  upset  the  neptunian  theory, 
and  established  in  its  place  the  plutonic  theory,  which  makes  fire  or  subter- 
ranean heat  the  main  agency  in  the  production  of  the  plutonic  and  met- 
amorphic  rocks. 

This  new  theory  does  not  admit  the  classification  of  primary  and  secondary 
rocks.  The  first  rocks  ever  produced,  which  formed  the  first  thin  crust  of  our 
globe,  were  dissolved  by  water  and  removed  to  other  localities,  where  they 
furnished  the  constituents  of  the  sedimentary  formations.  Even  a  large 
portion  of  these  have  been  ground  up  by  weather  and  water,  to  provide  the 
material  for  later  deposits.  Rocks  of  all  the  different  classes  have  been  formed, 
during  the  past,  simultaneously,  and  may  be  in  process  of  formation  at 
the  present  time.  The  terms  primary  and  secondary  are,  therefore,  obsolete, 
inasmuch  as  they  indicate  the  comparative  age  of  the  different  rocks. 

SEDIMENTARY  OR  STRATIFIED  ROCKS. 

Though  all  the  different  classes  of  rocks  are  of  great  interest  to  the  geologist, 
still  the  most  important  of  all  is  that  including  the  sedimentary  formations. 
The  rocks  of  this  class  are  always  arranged  in  layers  or  strata,  and  they  are, 
therefore,  generally  referred  to  as  stratified  rocks.  They  are  of  greater  impor- 
tance to  the  geologist  than  the  other  formations,  because  they  furnish  him  the 
main  material  for  his  investigations.  Most,  if  not  all,  of  them  have  been 
formed  since  the  beginning  of  organic  life  on  our  planet,  as  proved  by  the 
remains  or  traces  of  animal  and  vegetable  organism  preserved  in  their  strata. 

The  most  important  among  the  different  points  which  the  geologist  has  to 
consider  in  regard  to  the  sedimentary  rocks,  are :  their  mineral  composition, 
their  arrangement  in  strata,  their  relative  age,  and,  most  of  all,  their  organic 
remains. 

In  regard  to  their  mineral  composition,  we  may  divide  them  into  three 
groups,  the  siliceous,  or  arenaceous  rocks ;  the  clayey,  or  argillaceous  rocks  ; 
and  the  calcareous  rocks,  or  limestone.  The  main  constituent  of  the  first 
group  is  silica,  in  the  form  of  quartz-grains  or  sand  ;  that  of  the  second  group 
is  clay,  a  mixture  of  siliceous  matter,  with  a  large  amount  of  alumina  and 
oxide  of  iron,  and  that  of  the  third  group  is  carbonate  of  lime.  It  is  impos- 
sible to  separate  these  three  groups  by  a  well  defined  division  line.  Some 
rocks  form  a  kind  of  connecting  link  between  the  first  and  second,  and  others 
between  the  second  and  third  group,  while  again,  others  may  combine  the 
siliceous  and  calcareous  rocks.  The  first  group  is  represented  by  sandstone, 


A    SKETCH    OF    GEOLOGY.  9 

the  second  by  shale,  and  the  third  by  limestone.  Argillaceous  rocks  are 
easily  identified  by  the  peculiar  earthy  odor  which  they  emit  when  breathed 
upon,  while  the  limestones  may  be  detected  by  the  aid  of  muriatic  acid,  which 
causes  effervescing  when  applied  to  them.  Upon  sandstone  acids  have  no 
effect  whatever. 

STRATIFICATION. — Stratification  is  the  arrangement  of  rocks  into  different 
layers  or  beds.  It  is  a  characteristic  feature  of  all  the  sedimentary  forma- 
tions. Stratification  can  only  be  produced  by  sedimentation,  and  the  latter 
can,  as  far  as  geological  strata  are  concerned,  only  take  place  in  water  charged 
with  solid  or  earthy  matter,  which  is  kept  in  suspense  in  the  shape  of  mud. 
Solid  material  has  generally  a  greater  density,  or  specific  gravity,  than  water, 
and,  therefore,  can  be  kept  in  suspense  by  the  latter  only  so  long  as  the  lateral 
motion  of  the  water  overcomes  the  action  of  gravitation.  As  soon  as  the 
water  ceases  to  move,  the  mud  falls  to  the  bottom,  where  it  forms  the  sediment 
which  afterwards,  under  the  enormous  pressure  of  superimposed  masses, 
transforms  into  solid  rock.  If  such  sediment  formation  had  gone  on  continu- 
ously, and  always  under  exactly  the  same  conditions,  throughout  a  whole 
geological  period,  all  the  rocks  of  that  formation  would  form  a  solid,  un- 
broken mass.  But  the  sediment  formation  suffered  frequent  interruptions, 
extending  over  shorter  or  longer  periods,  and  was  subjected  to  many  changes 
in  its  material.  These  circumstances  caused  a  differentiation  in  the  deposits. 
Any  interruption  of  the  formation,  or  any  change  in  the  material,  were  indi- 
cated by  lines  or  planes  of  separation,  while  the  different  layers,  thus  produced, 
were  distinguished  by  color  and  texture. 

The  solid  or  earthy  materials  with  which  the  waters  are  charged,  are  derived 
partly  from  the  dry  land  by  the  influence  of  heat,  frost  and  rain,  and  partly 
by  the  never- resting  waves  of  the  oceans  grinding  up  the  cliffs  and  beaches  of 
the  seashores.  These  agencies  are  employed  to  reduce  the  elevations  of  the 
dry  lands  to  the  level  of  the  oceans,  and,  if  they  were  not  counteracted  by 
other  forces,  would  accomplish  their  task  in  less  than  six  millions  of  years. 
It  is  estimated  that  the  average  elevation  of  all  the  continents  and  islands  does 
not  amount  to  fully .  one  thousand  feet ;  and,  on  the  other  hand,  the  work 
accomplished  by  denudation  is  computed  to  be  one  foot  in  six  thousand  years, 
extending  over  the  whole  area  elevated  above  the  ocean.  Such  calculations 
are  only  mere  approximations,  based  upon  conditions  which  may  change 
considerably  in  the  course  of  time,  and  should  never  be  used  for  framing 
deductions,  without  making  great  allowances.  That  the  work  of  denudation 
must  have  been  different  during  the  different  ages  of  the  past,  can  not  be 
doubted.  There  were  periods  when  a  very  high  temperature  prevailed  all 
over  the  earth,  from  the  poles  to  the  equator,  causing  a  heavy  rainfall,  and 
lending  the  water  a  greater  dissolving  power,  circumstances  which  must  have. 

GKOL.   SUR. — 2 


10  PALAEONTOLOGY    OF    KENTUCKY. 

produced  greater  denudation.  Then,  again,  other  periods  set  in,  when  the 
temperature  of  our  globe  was  very  low,  when  the  excessive  heat  of  former 
ages  was  replaced  by  excessive  cold.  Frost  is  a  very  powerful  agent  in  the 
destruction  of  rocks.  The  hardest  material  which  admits  water  into  its  pores 
will  be  crumbled  to  dust  by  this  destructive  force.  Here,  again,  denudation 
must  have  been  very  large.  Between  these  extremes  in  temperature,  our  planet 
experienced  some  moderate  climate  which  had  not  such  a  destructive  influence 
upon  the  solid  material  of  our  earth's  crust. 

STKATA  AND  LAYERS. — These  two  terms  are  generally  used  as  synonymous, 
but  some  geologists  make  a  distinction  between  them.  They  use  the  term 
layer  for  each  single  member  of  stratified  rock,  and  apply  the  term  strata  to 
beds  of  the  same  material.  Thus,  if  a  section  shows  in  its  lower  half  limestone, 
and  in  its  upper  half  sandstone,  it  contains  only  two  strata,  though  it  may 
show  a  great  many  layers. 

Layers  and  strata  vary  in  thickness  from  an  inch,  and  less,  to  many  feet. 
Very  thin  layers  are  called  laminae,  and  for  thin  strata,  the  term  seams  is  used. 
If  all  the  strata  had  remained  undisturbed  in  their  original  position,  all  would 
be  nearly  horizontal,  and  parallel  to  each  other ;  but  the  many  upheavals  and 
depressions  to  which  our  earth's  crust  has  been  subjected,  have  disturbed  their 
original  horizontal  and  parallel  arrangement,  and  we  now  find  them  occupying 
every  imaginable  position  in  relation  to  each  other.  Wherever  two  sets  of 
strata  or  layers  are  nearly  parallel  to  each  other,  it  proves  that  the  older  set 
was  not  disturbed  in  its  original  position  before  the  younger  or  later  one  was 
deposited  upon  it ;  but  whenever  the  upper  strata  rests  on  the  edges  of  those 
below,  these  latter  have  been  disturbed  before  the  formation  of  the  upper 
ones  took  place.  In  the  first  case,  where  the  parallelism  of  the  strata  is  main- 
tained, they  are  said  to  be  conformable;  but  whenever  the  planes  of  the  upper 
layers  rest  on  the  edges  of  the  lower  ones,  they  are  called  unconformable. 
Conformability  of  strata  indicates  a  period  of  rest,  whilst  unconformability  is 
a  certain  proof  of  disturbance.-  Any  movement  in  the  earth's  crust  must  pro- 
duce some  changes  in  its  layers  or  strata,  resulting  either  in  a  bending  or 
breaking  of  the  same,  whereby  fissures,  folds  and  faults  are  originated.  Fis- 
sures are  rents  caused  by  breakage,  without  any  displacement  of  the  rock  on 
either  side  of  the  fracture,  below  or  above  their  former  level ;  but,  whenever 
the  masses  on  one  side  or  the  other  have  changed  their  positions,  either  by 
elevation  or  depression,  the  rent  becomes  a  fault.  According  to  the  great 
difference  in  the  magnitude  of  the  forces  producing  the  faults,  the  size  of  the 
latter  must  also  differ  greatly.  We  find  them  measuring  from  an  inch  and 
less,  to  many  hundred  feet.  Faults  are  of  great  inconvenience  to  miners, 
especially  where  they  appear  of  considerable  size.  Folds  of  strata  are  the 
result  of  their  bending  without  breaking ;  they  differ  in  size  from  a  few  feet 


A    SKETCH    OF    GEOLOGY.  11 

to  many  miles,  and  form,  very  often,  extensive  valleys  and  mountains.  Strata 
are  very  seldom  found  perfectly  horizontal;  they  may  be  so  for  a  short  distance, 
but,  extending  over  a  larger  area,  they  will  always  show  a  certain  amount  of 
curvature.  These  curves  bending  inward — that  is,  with  their  convexity  toward 
the  center  of  earth — are  forming  troughs ;  bending  outward,  they  form  arches. 
A  line  running,  in  a  series  of  strata,  through  the  highest  point  of  their  arches, 
is  called  their  anticlinal  axis,  and  the  line  running  through  the  lowest  \  oint  of 
their  troughs  is  known  as  their  synclinal  axis.  If  no  denudation  had  inter- 
fered, we  would  always  find  the  anticlinal  axis  to  correspond  with  elevations, 
and  the  synclinal  with  valleys ;  but,  since,  by  the  influence  of  weather  and 
water  the  figuration  of  our  earth's  surface  has  greatly  changed,  we  often  meet 
with  anticlinal  valleys  and  synclinal  hills.  The  correct  location  of  these  lines 
is  often  of  great  importance  to  the  geologist  in  surveying  a  certain  district  or 
country,  which  he  can  easily  accomplish  if  he  bears  in  mind  that  his  proceed- 
ing from  older  upon  younger  strata  leads  him  towards  the  synclinal ;  and  vice 
versa,  if  he  proceeds  from  younger  upon  older  formation  he  approaches  an 
anticlinal. 

Two  other  important  features  of  the  stratified  rocks  are  their  dip  and  strike. 
Upon  these,  to  a  great  extent,  depends  the  peculiar  topography  of  the  earth's 
surface. 

Dip  is  the  amount  of  the  deflection  of  strata  from  the  horizontal  or  level 
line  ;  it  is  measured  by,  or  expressed  in,  degrees.  If  a  layer  has  a  dip  of  forty- 
five  degrees,  it  is  bent  downward,  and  forms  with  the  horizontal  surface  an 
angle  of  forty-five  degrees.  Wherever  the  dip  increases  to  an  angle  of  ninety 
degrees,  the  strata  stand  on  their  edges  in  a  vertical  position.  Strike  is  the 
horizontal  line  drawn  at  right-angles  to  the  direction  of  the  dip.  Rocks  with 
a  southern  or  northern  dip,  will  have  an  eastern  or  western  strike.  As  long 
as  the  dip  of  certain  strata  runs  in  the  same  direction,  their  strike  is  indicated 
by  a  straight  line  ;  but  as  soon  as  the  dip  changes  its  direction,  the  strike  will 
assume  the  shape  of  either  a  broken  or  curved  line.  Eocks  with  great  dip 
produce  a  broken  undulating  country,  and  in  accordance  with  the  curved  or 
straight  lines  of  the  strike,  we  find  the  hills  and  valleys  respectively  winding 
or  rectilineal. 

PALEONTOLOGY. 

Palaeontology  treats  of  the  animals  and  plants  which  inhabited  our  planet 
during  former  periods,  and  may,  therefore,  be  properly  styled  the  natural 
history  of  by -gone  ages.  From  zoology  and  botany,  it  differs  only  in  so  far 
as  its  objects  belong  mostly  to  an  extinct  fauna  and  flora,  the  remains  or 
traces  of  which  are  imbedded  in  the  rocks  and  soils  of  the  earth's  crust.  Palae- 
ontology forms  a  science  of  itself ;  but  on  account  of  its  intimate  connection 
with  geology,  it  is  generally  considered  as  only  a  branch  of  the  latter.  The 


12  PALEONTOLOGY    OF    KENTUCKY. 

objects  with  which  palaeontology  deals  are  known  under  the  name  of  "  fossils," 
a  term  designating  bodies  "dug  out  of  the  ground,"  and  which  was  formerly 
applied  to  metals  and  rocks,  as  well  as  to  organic  remains.  At  present  the 
word  fossil  is  used  in  a  more  restricted  sense,  applying  only  to  such  geological 
objects  from  which  science  may  deduce  information  about  the  organic  life  of 
the  past.  These  objects  mainly  consist  in  remains  of  animals  and  plants,  such 
as  shells,  teeth  and  bones ;  or  stems,  leaves  and  fruits ;  but  they  also  include 
the  burrows  and  tracks  of  annelids,  the  footprints  of  saurians  and  other  ani- 
mals, and  even  the  droppings  of  fishes  and  reptiles,  which  are  known  under 
the  name  of  coprolites.  Some  geologists  class  among  the  fossils  even  objects 
produced  by  man,  such  as  arrow-heads,  spear-heads  and  canoes  found  in  the 
gravel  and  clay  beds  of  our  fields  and  river  shores ;  but,  inasmuch  as  they 
properly  belong  to  archaeology,  they  can  not  be  counted  among  the  fossils. 

The  real  nature  of  fossils  was  known  more  than  five  hundred  years  before 
the  Christian  era,  by  Xenophanes.  He  observed  the  fossil  remains  in  the 
quarries  of  Syracuse,  consisting  of  marine  shells  and  fish-bones.  He  recognized 
them  as  the  remains  of  real  animals,  that  had  lived  there  at  the  bottom,  of 
the  sea,  where  they  were  imbedded  in  mud,  which  afterwards  hardened  into 
the  rocks  then  inclosing  them.  He  also  laid  down  the  general  proposition,  that 
the  geographical  features  of  our  earth  are  not  constant,  but  that,  where  land 
now  is,  sea  has  been,  and  where  sea  now  is,  land  has  been.  Afterwards  this 
clear  conception  of  the  real  nature  of  fossils  appears  to  have  been  lost,  until 
the  end  of  the  seventeenth  century,  when  Nicholas  Steno,  Professor  of  anat- 
omy in  Florence,  though  a  Dane  by  birth,  gave  them  again  a  correct  explan- 
ation, and  revived  the  theory  of  Xenophanes. 

Before  Steno,  during  the  fourteenth,  fifteenth,  sixteenth  and  seventeenth 
centuries,  fossils  were  regarded  as  mere  figured  stones,  portions  of  mineral 
matter  which  have  assumed  the  forms  of  leaves  and  shells  and  bones,  just  as 
those  portions  of  mineral  matter  which  we  call  crystals,  take  on  the  form  of 
regular  geometrical  bodies.  Others  considered  them  the  products  of  the  germs 
of  animals  and  of  the  seeds  of  plants,  which  have,  as  it  were,  lost  their  way, 
in  the  bowels  of  the  earth,  and  achieved  only  an  imperfect  and  abortive  devel- 
opment. These  opinions  appear  to  us  ridiculous,  and  we  are  inclined  to  sneer 
at  our  ancestors  for  entertaining  such  ideas  about  a  matter  which  is  now  so 
clear  and  simple.  People  who  believed  in  spontaneous  generation,  could  have 
no  difficulty  in  taking  fossils  for  sports  of  nature,  and  we  know  that  spon- 
taneous generation  was  generally  believed  in  up  to  the  present  century ;  and, 
even  to-day,  thousands  of  people,  laying  claim  to  a  fair  education,  still  adhere 
to  that  belief  These  erroneous  ideas  about  the  nature  of  fossils  were,  long 
after  Steno' s  correct  interpretation,  maintained  among  common  people,  but 
men  of  science  became  more  and  more  convinced  of  the  correctness  of 


A    SKETCH    OF    GEOLOGY.  l£ 

Xenophanes'  theory.  To-day,  every  person  who  has  gained  an  insight  into 
palaeontology,  knows  that  the  fossils  found  in  most  of  the  sedimentary  rocks 
are  originated  by  animal  or  vegetable  remains,  which,  became  imbedded  in  the 
mud  at  the  bottom  of  the  sea,  during  former  ages.  In  speaking  of  fossils,  we 
generally  describe  them  as  remains  of  animals  and  of  plants,  which  is  not 
in  accordance  with  the  facts,  at  least  not  for  the  majority  of  them,  inasmuch 
as,  in  the  larger  number,  not  a  particle  of  organic  matter  is  preserved,  and 
only  the  form  of  the  imbedded  body  retained.  The  original  animal  or  vege- 
table substances  dissolved  and  became  replaced  by  calcareous,  siliceous  and 
other  minerals.  The  remains,  therefore,  underwent  an  active  transformation 
into  stone,  or  became,  as  we  call  it,  petrified.  Fossils  thus  transformed  or 
changed,  are  classed  together  under  the  name  of  petrifactions. 

This  term  is  very  often  used  as  a  synonym  for  fossils,  but  erroneously ; 
because  not  every  fossil  has  passed  through  a  petrifying  process,  while  there  are 
many  belonging  to  younger  formations,  that  have,  outside  of  form  and  struc- 
ture, retained  also  the  color  and  organic  matter  of  the  original  remains.  Every 
petrifaction  is  a  fossil,  but  not  every  fossil  is  a  petrifaction.  The  process  by 
which  the  transformation  of  organic  remains  into  mineral  bodies  is  produced, 
is  of  a  chemical  nature,  and  depends  upon  conditions  not  yet  fully  under- 
stood. 

We  must  distinguish  between  petrifactions  and  incrustations,  although  the 
latter  are  often  classed  among  the  former.  Incrustations  are  generally  pro- 
duced in  springs,  whose  waters  are  charged  with  a  considerable  amount  of 
calcareous  matter,  which  settles  upon  immersed  bodies,  like  flowers  and 
branches,  or  shells  and  bones,  inclosing  them  with  a  mineral  coat  or  crust, 
but  never  permeating  them,  as  is  done  in  the  case  of  petrifaction.  By  break- 
ing such  incrustations  we  find,  either  the  inclosed  bodies  unchanged,  or,  if 
they  have  disappeared,  the  place  formerly  occupied  by  them  *a  hollow  mould. 

Another  transformation  of  animal  matter  is  by  many  erroneously  classed 
among  petrifactions.  We  sometimes  notice  in  public  papers  reports  of  cases 
where  human  bodies,  resurrected  after  some  years  of  interment,  have  been 
found,  not  only  well  preserved  in  form,  but  so  hard  and  stiff,  and  so  much 
increased  in  weight,  as  to  appear  completely  changed  into  stone.  Such  cases 
are  looked  upon  by  a  great  many  people  as  a  kind  of  miracle,  while,  really, 
they  are  nothing  more  than  the  result  of  a  chemical  process  by  which  the 
animal  fat  has  been  converted  into  a  sort  of  wax.  Transformations  of  this 
kind  occur  only  in  bodies  buried  in  wet  places,  where  they  are  completely 
submerged  by  underground  water  charged  with  antiseptic  ingredients.  As 
soon  as  these  bodies  are  removed  from  their  original  resting  place,  they 
commence  to  decompose,  a  fact  clearly  showing  that  they  never  underwent 
the  process  of  petrifaction.  The  wax-like  material  into  which  the  fat  is  con- 


14  PALEONTOLOGY    OF    KENTUCKY. 

verted  is  called  adipocere.  It  was  first  discovered  by  the  French  scientist 
Fourcroy,  in  the  year  1787,  during  the  removal  of  the  cemetery  of  the  Inno- 
cents, in  Paris. 

USE   OF  FOSSILS. 

Collectors  of  geological  and  palaxmtological  specimens  are  often  objects  of 
wonder  and  curiosity  to  people  who  notice  them  closely  examining  rock-piles 
and  clay-banks.  What  are  those  fellows  doing  there  ?  What  are  they  hunt- 
ing for?  These  questions  are  asked,  without  exception,  by  almost  every 
person  passing  by,  and  if  the  men  of  science  show  the  things  they  are  looking 
for,  and  explain  their  origin  and  meaning,  they  may  consider  themselves  very 
fortunate  if,  in  ninety-nine  out  of  a  hundred  cases,  they  are  not  looked  upon  as 
fit  recruits  for  a  lunatic  asylum.  The  ignorance  prevailing  among  the  mass  of 
the  people,  about  objects  of  natural,  science,  and  especially  of  geology  and 
palaeontology,  is  appalling.  Such  ignorance  might  be  excused  among  the  lower 
classes,  who  had  neither  time  nor  opportunity  to  acquire  knowledge,  but  to 
find  it,  even  at  the  end  of  the  nineteenth  century,  among  the  majority  of 
persons  who  lay  claim  to  a  fair  and  liberal  education,  is  very  humiliating,  and 
proves  the  inefficiency  of  our  schools,  at  least  in  that  direction. 

Fossils  are  picked  up,  by  people  in  general  and  by  curiosity  hunters  in 
particular,  because  they  look  so  "pretty"  or  so  "strange,"  as  the  expression 
may  be;  but  that  these  pretty  and  strange-looking  things  are  of  the  greatest 
importance  to  science,  and  of  immense  service  to  industry,  is,  so  far,  known 
only  to  very  few,  outside  of  the  scientific  world.  Fossils  are  the  letters  with 
which  Nature  has  written  the  earth's  history,  in  a  language  intelligible  to 
every  student  of  natural  science,  whatever  nationality  he  may  claim.  They 
faithfully  report  to  us  the  different  processes  and  changes  through  which  our 
globe  has  passed  *  from  its  beginning  as  a  solid  body  to  the  present  day.  In 
them,  the  animal  and  vegetable  kingdoms  of  by-gone  ages  arise  from  their 
tombs,  and  present  themselves  to  the  investigation  of  science.  They  furnish 
the  indisputable  proof  that  the  organized  world  commenced  with  its  lowest 
forms,  and  developed  gradually  into  its  higher  types.  Mantell,  an  English 
geologist,  says  of  them:  "Fossils  have  been  eloquently  and  appropriately 
termed  medals  of  creation,  for,  as  an  accomplished  numismatist,  even  when 
the  inscription  of  an  ancient  and  unknown  coin  is  illegible,  can,  from  the  half 
obliterated  effigy  and  from  the  style  of  art,  determine  with  precision,  the 
people  by  whom,  and  the  period  when  it  was  struck ;  so,  in  like  manner,  the 
geologist  can  decipher  these  natural  memorials,  interpret  the  hieroglyphics 
with  which  they  are  inscribed,  and,  from  apparently  most  insignificant  relics, 
trace  the  history  of  beings,  of  whom  no  other  records  are  extant,  and  ascer- 
tain the  forms  and  habits  of  unknown  types  of  organization,  whose  races  were 


A    SKETCH    OF    GEOLOGY.  15 

swept  from  the  face  of  the  earth  long  before  the  appearance  of  man  and  his 
contemporaries."  The  fact  that  fossils  show  the  gradual  development  of 
organic  life  from  its  lowest  to  its  highest  types,  affords  to  science  the  means 
of  determining  the  relative  age  of  the  different  strata  in  which  they  are 
imbedded ;  rocks,  for  instance,  embracing  remains  and  traces  of  fishes,  must 
be  younger  than  others  in  which  only  fossils  of  shells  and  corals  are  contained ; 
or,  again,  strata  only  imbedding  seaweeds  and  other  low  forms  of  the  vegetable 
kingdom,  must  be  older  than  those  in  which  leaves  and  fruits  of  the  trees  of 
our  present  forests  are  found.  Fossils  tell  us  by  their  character,  and  by 
their  mode  of  preservation,  whether  they  have  lived  at  the  bottom  of  the 
ocean,  in  fresh  water  lakes  or  rivers,  or  on  the  dry  land.  If  they  lived  in 
the  seas,  they  also  inform  us  whether  these  were  quiet  or  stormy,  deep  or 
shallow.  By  the  data  deduced  from  fossils,  geologists  are  able,  to-day,  to  write 
the  geographies  of  former  geological  epochs,  and  to  mark  oat  on  maps  the 
exact  distribution  of  land  and  water  prevailing  on  our  globe  during  those 
periods.  What  the  compass  is  to  the  navigator,  guiding  him  across  the 
pathless  ocean  into  the  intended  port,  are  the  fossils  to  the  geologist  in  his 
scientific  investigations,  and  in  his  explorations  for  economical  and  industrial 
purposes.  They  not  only  tell  him  the  history  of  the  earth,  and  of  its  former 
inhabitants,  they  also  show  him  the  fields  where  the  gold  and  diamond  hunter 
may  find  those  brilliant  treasures  with  which  our  daughters  like  to  heighten 
and  brighten  their  natural  charms.  They  indicate  the  places  where  to  dig  suc- 
cessfully for  the  briny  water  which  furnishes  our  table  with  the  most  indis- 
pensable spice,  or  for  the  valuable  oil  illuminating  our>  houses  and  parlors. 
They  also  locate  the  mines  from  which  we  extract  that  invaluable  mineral  which 
not  only  affords  us  comfort  at  home,  but  also  speeds  our  travels  across  the 
oceans  and  the  plains. 

Fossils  are  the  letters  in  the  geological  alphabet.  To  read  the  latter  you 
must  know  the  former.  Without  their  thorough  understanding,  no  successful 
study  of  geology  is  possible. 

GEOLOGICAL  PERIODS. 

During  the  infancy  of  the  geological  science,  it  was  generally  believed  that 
different  periods  had  existed  in  former  ages,  which  were  separated  by  sharply 
defined  division  lines,  and  that  each  period  possessed  its  own  creation  ;  which 
meant  that  all  the  different  species  of  animals  and  plants  of  a  certain  period 
were  created  and  destroyed  during  that  period,  and  that,  for  the  succeeding 
epoch,  an  entirely  new  creation  had  to  take  place.  This  belief  in  the  total 
destruction  of  all  existing  life  at  the  end  of  the  different  geological  periods, 
called  cataclysm,  originated  from  the  fact  that  different  groups  of  strata  con- 
tain different  groups  of  fossils,  and  was  upheld  by  the  belief  in  a  priori  ere- 


10  PALAEONTOLOGY    OF    KENTUCKY. 

ation  of  each  species.  Corresponding  with  those  periods,  the  stratified  rocks 
were  divided  into  different  formations. 

The  rapid  progress  of  the  geological  science  has  expunged  the  division  lines 
between  the  periods,  and  has  upset  the  theory  of  cataclysm.  The  existence  of 
different  groups  of  fossils  in  different  strata  can  not  be  denied ;  but  a  more 
careful  examination  of  the  fossils  has  already  shown,  and  hereafter  will  show 
more  conclusively,  that  the  existing  differences  are  not  the  result  of  new  cre- 
ations, but  are  produced  by  the  gradual  modifications  occurring  in  species 
exposed  to  changes  in  their  surroundings  during  the  course  of  many  centuries. 
The  theory  of  evolution,  now  generally  accepted  by  all  men  of  science,  has 
destroyed  the  theory  of  cataclysm,  as  well  as  the  belief  in  an  a  priori  creation 
of  each  single  species.  The  division  of  the  geological  time  into  periods,  and 
of  the  stratified  rocks  into  formations,  though  based  upon  erroneous  supposi- 
tions, has  proved  to  be  of  great  convenience  to  geologists,  and  is,  therefore, 
maintained.  The  dividing  lines,  however,  are  not  fixed  by  nature,  but  may 
be  shifted  by  arbitration.  The  whole  geological  time,  from  its  beginning  to  the 
present  day,  is  divided  into  four  great  divisions  called  ages.  These  are  as  fol- 
lows : 

1.  Azoic  AGE,  embracing  the  time  from  the  beginning  of  the  earth  as  a  solid 
body  to  the  appearance  of  life  in  the  shape  of  either  animals  or  plants. 

2.  PAL^EOZIC  AGE,  beginning  with  the  appearance  of  organic  forms,  and  ter- 
minating with  the  close  of  the  coal  formation. 

3.  MESOZOIC  AGE,  beginning  at  the  end  of  the  coal  formation,  and  closing  at 
the  appearance  of  mammals. 

4.  CENOZOIC  AGE,  embracing  the  balance  of  time  up  to  the  present  day. 
Corresponding  with  this  division  of  time,  we  divide  all  the  rocks  into  the 

four  groups  of  azoic,  palaeozoic,  mesozoic  and  cenozoic  rocks,  according  to  the 
age  in  which  their  respective  formation  took  place.  The  first  group  of  rocks 
is  of  little  or  no  interest  to  the  palaeontologist,  inasmuch  as  it  does  not  contain 
any  traces  of  life ;  still,  what  we  to-day  consider  ^azoic,  or  bare  of  life,  may, 
to-morrow,  disclose  forms  of  undoubted  organic  character.  Not  many  years 
ago  all  the  metamorphic  rocks  were  considered  azoic;  but  since  Canadian  geolo- 
gists have  discovered  the  Eozoan  canadense,  and  have  also  established  the  fact 
that  numerous  traces  of  coal  and  graphite  are  to  be  found  in  these  rocks,  the 
existence  of  some  kind  of  life  during  the  formation  of  that  group  can  not  be 
doubted  any  longer.  As  soon  as  the  presence  of  life  during  the  formation  of 
those  rocks,  which  heretofore  were  classed  among  the  azoic,  is  definitely  settled, 
those  rocks  have  either  to  be  removed  to  the  palaeozoic  group,  or,  as  Professor 
Dawson,  of  Canada,  has  proposed,  a  new  group,  to  be  called  the  Eozoic,  has  to 
foe  established  for  their  reception, 


A    SKETCH    OF    GEOLOGY.  17 

All  the  different  metamorphic  rocks  constitute  together  the  Archaean  forma- 
tion, which  is  subdivided  into  the  Laurentian  and  Huronian  groups.  The 
Laurentian  group  forms  the  base  of  the  whole  geological  column  of  sediment- 
ary rocks.  It  derives  its  name  either  from  the  St.  Lawrence  river  or  from  the 
Laurentian  mountains  in  Canada,  where  it  is  exposed  over  an  extensive  area. 
In  the  United  States  we  find  it  cropping  out  in  New  York,  where  it  forms  the 
Adirondack  mountains  ;  also  in  Michigan  and  Tennessee,  and  in  a  few  other 
States.  Its  thickness  in  Canada  is  estimated  to  be  about  six  miles,  or  more 
than  30,000  feet.  About  the  middle  of  its  column  are  the  strata  containing 
the  Eozoan  canadense,  the  real  nature  of  which  is  still  involved  in  some  doubt. 
However,  it  appears  that  a  majority  of  geologists  have  accepted  it  as  the  fossil 
remains  of  a  Rhizopod,  and  consider  it  as  the  commencing  point  of  animal 
life. 

The  Huronian  group  has  received  its  name  from  Lake  Huron,  in  the  vicinity 
of  which  it  is  largely  developed  and  exposed.  It  overlies  the  rocks  of  the 
previous  group  in  a  manner  proving  its  later  origin.  The  dividing  line  between 
these  two  Archaean  groups  is  not  sharply  drawn.  The  absence  of  fossils  in 
these  rocks  compels  us  to  base  their  distinction  altogether  upon  their  litho- 
logical  characters,  which,  alone,  seldom  affords  a  safe  criterion  for  the  deter- 
mination of  groups.  The  thickness  of  the  Huronian  group  in  Canada  is 
estimated  to  exceed  10,000  feet.  None  of  these  Archaean  rocks  are  exposed 
in  the  State  of  Kentucky,  though  their  presence  at  great  depth  can  not  be 
doubted. 

The  rocks  formed  during  the  Palseozic  age  are  divided  into  three  formations  : 
the  Silurian,  the  Devonian  and  the  Carboniferous. 

SILTJKIAN  FORMATION. — This  formation  was  first  established  by  Sir  E.  T. 
Murchison,  the  celebrated  English  geologist.  He  named  it  after  the  ancient 
Silures,  the  former  inhabitants  of  that  portion  of  Britain  where  he  first  studied 
this  class  of  rocks.  Murchison  divided  this  formation  into  the  Upper  and 
Lower  Silurian,  a  subdivision  generally  accepted  by  the  geologists  of  Europe 
and  America,  and  which  answers  fully  for  most  purposes.  The  Lower  Silurian 
formation  is  the  most  important  on  account  of  its  large  extent  in  thickness,  as 
well  as  in  area.  It  is  subdivided  into  the  following  groups,  which  are  given 
in  ascending  order. 

1.  St.  John's  Group;  2.  Potsdam  Group;  3.  Calciferous  Group;  4.  Quebec 
Group ;  5.  Chazy  Group ;  6.  Birdseye  Limestone ;  7.  Black  Eiver  Group 
8.  Trenton  Group ;  9.  Utica  Slate ;  10.  Hudson  River  Group.  Some  of  these 
groups,  as  will  be  seen,  are  named  after  localities  where  they  are  prominently 
exposed,  while  others  have  received  their  name  from  the  peculiar  character 
of  the  rocks  which  they  embrace.  Of  all  these  different  groups,  the  Trenton 

OEOL.  SUB. — 3 


18  PALEONTOLOGY    OF    KENTUCKY. 

and  the  Hudson  River  groups  are  of  main  importance  to  Kentucky  geologists. 
These  two  cover  extensive  areas  of  our  State,  and  show  in  some  places  con- 
siderable thickness.  The  balance  are  either  wanting  in  Kentucky  altogether, 
or  exposed  in  only  very  few  and  very  limited  spots. 

The  Hudson  River  Group  is  generally  known  as  the  Cincinnati  Group,  on 
account  of  its  excellent  exposure  at  and  around  Cincinnati.  In  Kentucky,  the 
blue  limestone  of  the  Trenton  forms  the  surface-rock  of  that  rich  and  world- 
renowned  district  known  as  the  "Blue-grass  Country,"  and  is,  there,  the 
source  of  the  most  productive  soil  of  the  United  States.  In  consequence  of 
the  rapid  decomposition  of  this  rock,  when  exposed  to  the  influence  of  sun- 
shine and  rain,  it  keeps  the  soil  in  an  everlasting  virginity,  a  soil  which,  a 
thousand  years  from  to-day,  will  produce  as  well  as  it  does  at  present,  pro- 
vided all  other  conditions  remain  the  same.  The  Upper  Silurian  is  divided 
into  the  following  groups : 

1.  The  Oneida  Conglomerate  ;  2.  The  Medina  Sandstone ;  3.  The  Clinton 
Group ;  4.  The  Niagara  Group ;  5.  The  Onondaga  Salt  Group  ;  6.  The  Lower 
Helderberg  Group.  Of  these  subdivisions  of  the  Upper  Silurian,  only  the 
Clinton  and  the  Niagara  groups  deserve  especial  notice  as  Kentucky  forma- 
tions. The  Clinton  Group  is  only  found  in  few  and  isolated  places,  and  never 
attains  a  thickness  of  any  consideration.  The  Niagara  Group  embraces  the 
same  kind  of  rocks  which  form  the  bed  of  the  Niagara  river  at  its  world-re- 
nowned falls,  whence  it  derives  its  name.  In  Kentucky  it  neither  covers 
extensive  areas  nor  attains  great  thickness ;  but  it  furnishes,  in  some  places, 
excellent  building  stone.  Near  Louisville,  we  find  it  well  exposed  in  the 
quarries  east  of  the  city,  providing  Louisville  with  most  of  the  limestone 
required  for  building  purposes.  Here  the  Niagara  rocks  are  very  rich  in  fos- 
sils, which  are  mostly  well  preserved,  and  have  furnished  a  great  deal  of  the 
material  now  in  the  valuable  collections  of  several  Louisville  geologists,  and 
which  enables  science  to  acquire  an  extensive  knowledge  of  the  fauna  of  the 
Niagara  period. 

DEVONIAN  FORMATION.— This  formation  is  named  by  Murchison  after  Devon- 
shire, in  England,  where  it  is  prominently  represented  in  the  surface-rocks. 
Here  in  America  we  have  subdivided  it  in  the  following  groups : 

1.  Oriskany  Sandstone ;  2.  Upper  Helderberg  Group ;  3.  Hamilton  Group ; 
4.  Portage  Group ;  5.  Chemung  Group;  and  6.  Catskill  Group. 

The  Oriskany  sandstone  is  placed  here  at  the  base  of  the  Devonian  column, 
whilst  others  consider  it  as  the  youngest  member  of  the  Silurian  groups.  It  is 
extremely  difficult  to  decide  which  of  the  two  places  assigned  by  different 
geologists  to  the  Oriskany  sandstone,  is  the  proper  and  correct  one.  If,  in 
accordance  with  the  opinion  of  the  older  geologists,  the  Silurian  period  had 


A    SKETCH    OP    GEOLOGY.  19 

been  closed  by  a  cataclysm,  extinguishing  all  life  of  the  Silurian  time,  Nature 
itself  would  have  drawn  a  dividing  line  between  Silurian  and  Devonian  forma- 
tions which  could  not  be  misunderstood  by  anybody ;  but  no  cataclysm  ever 
took  place  ;  on  the  contrary,  the  transformation  of  the  Silurian  fauna  and  flora 
into  their  Devonian  forms  was  accomplished  by  slow  and  gradual  modifications, 
a  process  which  did  not  produce  partition  lines,  the  establishment  of  which  is 
thus  left  to  arbitration.  The  proper  way  to  find  out  the  correct  position  of  the 
Oriskany  sandstone,  is  to  carefully  examine  its  fossils ;  if  these  show  a  nearer 
relationship  to  those  of  the  Devonian  than  to  the  Silurian,  the  questionable 
group  belongs  to  the  younger  formation  ;  but  if  the  relationship  is  closer  to  the 
Silurian  forms,  said  group  should  be  transferred  to  the  Silurian  column.  In 
our  own  State,  we  find  the  Devonian  formation  represented  only  by  the  upper 
Helderberg  and  Hamilton  groups,  which  are  so  blended  together  that  it  is  en- 
tirely impossible  to  separate  them  from  each  other.  Fossils  characteristic  of 
either  of  these  groups  are  found  from  bottom  to  top  of  the  whole  Devonian 
columns  in  Kentucky.  The  Devonian  formation  does  not  cover  a  very  extensive 
field  in  our  State,  still  it  is  of  great  importance  for  economic,  as  well  as  for 
scientific  purposes.  It  furnishes  to  the  builder  rock,  cement  and  lime  ;  to 
the  farmer,  a  healthy  and  productive  soil ;  and  to  the  geologist,  those  pre- 
cious specimens  of  fossil  corals,  crinoids  and  shells,  which  nowhere  on  the  whole 
globe  can  be  found  in  such  abundance  of  specimens  and  species,  and  in  such 
excellent  state  of  preservation,  as  at  Louisville  and  its  vicinity.  The  widely 
known  Falls  of  the  Ohio  River  are  not  only  known  here  in  this  country  as  an 
obstruction  to  navigation,  but  they  are  known  to  geologists  of  the  whole  civil- 
ized world  as  the  great  store-house  where  the  Devonian  world  has  collected  the 
choicest  specimens  of  its  animal  kingdom. 

The  Upper  Helderberg  group  is  often  called  the  Corniferous  limestone,  or  the 
Corniferous  group,  on  account  of  the  great  mass  of  hornstone  which  it  contains. 
This  hornstone  is  found  in  great  abundance  in  all  of  our  Devonian  strata,  and 
it  would,  therefore,  be  advisable  to  designate  the  whole  Devonian  column  in 
Kentucky  as  the  Corniferous  group. 

CARBONIFEROUS  FORMATION. — This  formation  is  divided  into  Subcarbonifer- 
ous  and  Coal  Measures;  both  are  still  covering  a  large  territory  in  Kentucky, 
though  it  appears  that  their  former  original  extent  has  been  greatly  reduced  by 
denudation.  At  present  we  have  two  large  coal  fields  in  our  State ;  the  eastern, 
which  forms  a  part  of  the  Appalachian  coal  region,  and  the  western,  belonging 
to  the  Illinois  coal  fields.  Both  these  districts,  it  appears,  were  formerly 
united,  though  they  are  at  present  separated  from  each  other  by  a  broad  strip 
of  land  whose  surface-rocks  belong  either  to  the  Devonian  or  to  the  Silurian. 
That  the  Carboniferous  strata  originally  covered  this  dividing  strip  can  scarcely 


20  PALEONTOLOGY    OF    KENTUCKY. 

be  doubted,  when  we  find  the  many  knobs  by  which  it  is  covered  capped  with 
the  Carboniferous  formation.  Those  knobs  can  not  be  the  products  of  volcanic 
action.  The  undisturbed  horizontality  of  their  layers  proves  them  to  be  the 
result  of  denudation.  The  denuding  influence  of  heat,  frost  and  rain  appears 
to  be  too  insignificant  to  have  produced  such  an  amount  of  excavation  as  would 
have  been  necessary  to  cut  down  many  square  miles  of  land  from  their  former 
to  their  present  level — a  difference  in  some  places  amounting  to  several  hundred 
feet.  However,  we  must  always  bear  in  mind  that  geological  agencies  are 
enabled  to  do  their  enormous  work,  not  so  much  by  their  magnitude,  but 
mainly  by  their  perseverance  throughout  the  endless  spaces  of  geological 
times. 

Of  the  Subcarboniferous  we  distinguish  the  following  five  subdivisions  :  Kin- 
derhook,  Burlington,  Keokuk,  St.  Louis  and  Chester  groups.  It  is  doubtfu 
whether  the  Kinderhook  group  is  really  different  from  the  Chemung  group, 
and,  even  if  a  difference  exists,  it  remains  questionable  where  to  place  it  prop- 
erly, whether  with  the  Devonian  or  the  Subcarboniferous ;  its  fossils  show  a 
nearer  relationship  to  the  Devonian  fauna  than  to  that  of  the  superimposed 
strata  of  the  Subcarboniferous.  In  Kentucky  we  find  only  the  three  younger 
formations,  viz. ;  the  Keokuk,  the  St.  Louis  and  the  Chester,  which  form  a 
kind  of  border  around  the  coal  fields.  The  St.  Louis  limestone  gives  a  peculiar 
feature  to  the  country  of  which  it  forms  the  surface-rock.  In  its  strata  we 
find  the  many,  often  very  extensive  caverns,  and  the  surface  covered  over 
with  numerous  funnel-shaped  sink-holes.  All  the  formations  and  groups  so 
far  enumerated,  originated  during  the  Palaeozoic  Period ;  they  alone  are  of 
interest  to  Kentucky,  inasmuch  as  they  embrace  all  the  surface-rocks  of  our 
State. 

MESOZOIC  AGE.  —This  produced  the  following  three  groups :  Triassic,  Jurassic 
and  Cretaceous.  None  of  these  are  represented  in  our  State,  though  they 
cover  vast  areas  of  our  continent,  especially  the  Triassic  and  Cretaceous,  whilst 
the  Jurassic  is  only  recognized  in  the  Rocky  Mountains  and  on  its  western 
slope. 

CENOZOIC  AGE. — During  this  age,  which  reaches  to  the  present  time,  the 
Tertiary  formation  was  called  into  existence.  In  it  we  find  the  earliest  repre- 
sentatives of  the  different  genera  and  species  of  animals  and  plants  which  to- 
day inhabit  our  planet.  The  subdivisions  of  the  Tertiary  are  Eocene,  Miocene 
and  Pliocene. 

Of  living  or  recent  species,  the  Eocene  contains  3  to  4  per  cent.  ;  the  Miocene 
from  18  to  20  per  cent.,  and  the  Pliocene  from  35  to  95  per  cent,  according  to 
Ly ell's  definition  of  these  different  groups. 

In  the  localities  where  Lyell  studied  these  different  rocks,  there  was  a  clear 


A    SKETCH    OF    GEOLOGY.  21 

line  of  demarkation  between  the  groups  as  he  organized  them,  and  in  each 
group  he  found  the  above  stated  percentage  of  recent  species  ;  but  other  locali- 
ties of  Tertiary  rocks  showed  more  than  4  and  less  than  18  per  cent. ,  and  others 
again  more  than  20  and  less  than  35  per  cent,  of  living  species  among  their 
fossils.  The  question  there  and  then  arose,  to  which  of  the  groups  such  strata 
should  be  attached  ?  This  question  is  solved  by  placing  them  in  those  groups 
with  which  their  fossils  show  the  nearest  relationship. 

MOLLUSCA. 

Mollusca  form  one  of  the  great  animal  sub-kingdoms  ;  their  name  is  derived 
from  the  Latin  word  "Mollis,"  meaning  soft,  on  account  of  the  soft  consistency 
of  their  body.  This  name  was  given  to  them  by  the  French  savant,  Cuvier. 
This  sub -kingdom  embraces  the  Mollusca  proper  and  the  Molluscoids.  The 
latter  include  the  Polyzoa  or  Bryozoa  and  the  Ascidians.  The  Ascidians  hav- 
ing no  shell,  but  instead  only  a  kind  of  leathery  sack,  are  not,  so  far,  found  in 
a  fossil  condition.  The  Bryozoa  were  formerly  classed  with  the  Corals  on 
account  of  the  resemblance  of  their  calcareous  support  with  those  forms,  but 
a  closer  study  of  the  animals  themselves  proves  their  nearer  relationship  with 
the  Mollusca.  Inasmuch  as  the  following  monograph  only  treats  of  the  fossil 
remains  of  the  Mollusca  proper,  I  deem  it  sufficient  to  limit  my  description  to 
the  latter. 

The  soft  condition  of  the  animals  of  this  class  makes  it  necessary  to  provide 
them  with, a  protection  in  some  shape  or  form.  This  is  given  them  either  by  a 
calcareous  envelope  called  their  shell,  or  by  a  leathery  sack  or  mantle  surround- 
ing the  body.  This  mantle  is  possessed  by  every  Mollusca,  whether  it  is  pro- 
vided with  a  shell  or  not;  but  the  mantle  of  those  without  shell  is  more 
leathery  and  better  adapted  for  protection  than  the  mantle  of  the  shell-bearers. 
The  shells  are  either  of  one,  two  or  several  pieces,  and  are  accordingly  called 
univalves,  bivalves  and  multivalves.  The  common  garden  snail  belongs  to  the 
first,  the  river  mussel  to  the  second,  and  the  Chitons  to  the  last  group.  Some 
of  the  Mollusca  have  a  regular  head  furnished  with  eyes,  tentacles,  and  a  mouth 
with  jaws  and  teeth.  This  class  is  called  Encephala.  The  balance,  having  no 
head,  are  known  as  Acephala.  The  first  group  is  divided  into  Cephalopoda, 
Gasteropoda  and  Pteropoda;  the  second  into  Brachiopoda  and  Lamellibran- 
chiata. 

CEPHALOPODA,  meaning  head-footed,  so  named  because  their  arms  or  feet  are 
arranged  around  their  mouth.  To  this  class  belong  the  Nautilus,  the  Argo- 
naut and  the  cuttle-fish  of  the  present  fauna,  and  the  Ammonites,  Cereatites 
and  Belemnites  of  former  ages.  The  bodies  of  most  of  them  are  symmetrical, 
that  is,  both  halves  of  their  bodies  are  identical  in  parts  and  size;  their  loco- 


22  PALEONTOLOGY    OF    KENTUCKY. 

motion  is  produced  either  by  the  muscular  feet  surrounding  their  mouths,  or 
by  two  fins  attached  to  the  sides  of  their  body,  or,  again,  by  the  forcible  ex- 
pulsion of  water  through  a  tube,  called  the  siphon.  There  are  two  orders  of 
Cephalopods :  Dibranchiata  and  Tetrabranchiata,  the  first  possessing  two  and 
the  second  four  branchiae. 

The  first  order  includes  the  cuttle-fishes  ;  they  are  all  naked,  with  the  ex- 
ception of  the  Argonaut.  Their  soft  body  is  supported  by  an  internal  shell. 
Plate  I,  figure  12,  shows  the  complete  animal  of  the  Sepia  officinalis ;  and  Plate 
I,  figure  16,  is  a  Belemnite,  or  the  internal  shell  of  one  of  the  dibranchiate 
Cephalopods.  Most  all  the  species  of  this  order  are  provided  with  an  ink-bag, 
the  contents  of  which  they  discharge  when  pursued  by  their  enemies.  Of  the 
second  order,  the  Tetrabranchiata,  only  very  few  species  are  living  at  the  pres- 
ent time.  Plate  I,  figure  24,  shows  the  Nautilus  pompilius,  the  main  repre- 
sentative of  the  tetrabranchiate  Cephalopods  of  the  present  seas.  The  oceans 
of  former  ages  were  swarming  with  species  of  this  order,  fossil  forms  of  which 
are  figured  on  Plate  I,  figures  1,  2,  18  and  19.  Their  shells  are  internally 
divided  into  cells  or  chambers  (see  Plate  I,  figures  1  and  24),  by  a  series  of 
partitions  called  the  septa  (see  Plate  I,  figure  245),  connected  by  a  tube  called 
the  siphon  or  siphuncle,  shown  by  c,  Plate  I,  figure  24.  Only  the  last  chamber, 
called  the  body-chamber,  is  occupied  by  the  animal,  while  the  others  are  empty 
and  serve  as  air-chambers.  In  fossil  specimens  very  often  the  outer  shell  is 
removed,  and  the  edges  of  the  septa  are  seen  (Plate  I,  figures  18  and  19), 
which  are  called  sutures.  Their  form  serves  to  distinguish  different  genera ; 
they  are  curved  in  Nautilus  and  Orthoceras,  zigzag  in  Goniotites,  or  foliaceous 
in  Ammonite. 

The  siphuncle  is  also  of  great  importance  in  determining  genera ;  its  shape 
and  location  have  to  be  noticed  by  the  student  of  Palaeontology.  Its  shape  is 
so  variable  that  it  is  impossible  to  give  here  a  sufficient  explanation  of  the 
same,  whilst  its  siphuncle  may  be  located  either  in  the  center  of  the  shell  or 
in  its  dorsal  or  ventral  lines,  or  even  on  either  of  its  sides.  The  opening  of 
the  body-chamber  is  called  its  aperture,  which,  in  different  species  and  genera, 
assume  different  shapes,  and  is  generally  closed  by  a  calcareous  plate,  called 
the  operculum. 

GASTEROPODA. — This  class  includes  land  and  water-snails,  which  are  either 
naked  or  provided  with  a  shell.  They  received  their  name  because  their  loco- 
motion is  accomplished  by  the  lower  part  of  their  body,  which  is  provided 
with  strong  muscles,  and,  by  its  contractions  and  expansions,  serves  them  as  a 
foot.  (See  Plate  I,  figure  13.)  Their  shells  are  generally  univalve,  either 
spiral  or  tubular,  but  a  few  are  multivalve,  the  Chitons  (see  Plate  I,  figure  11). 
In  the  spiral  shells  we  have  to  notice  the  following  parts :  see  Plate  I,  figure 


A    SKETCH    OF    GEOLOGY.  23 

2,  a,  the  apex ;  C,  c  and  d,  sutures  ;  a  to  f,  the  spire ;  g,  the  aperture.  In 
figure  14  of  the  same  plate,  "a"  is  the  posterior  canal,  "C"  the  anterior  canal, 
and  "d"  the  outer  lip  of  the  aperture.  Each  full  turn  of  the  spiral  is  called  a 
whorl.  The  axis  (see  Plate  I,  figure  23),  ("a"),  around  which  the  whorls  are 
coiled,  is  either  solid  or  it  is  hollow,  as  may  be  seen  in  Plate  I,  figure  10.  In 
this  case  the  shell  is  called  perforated  or  umbellicated.  Nearly  all  the  shells 
are  dextral,  or  right-handed  ;  others  are  sinistral,  or  left-handed ;  see  Plate  I, 
figures  14  and  15.  The  first  is  dextral,  the  second  sinistral.  In  a  few  species 
the  shell  is  regularly  sinistral ;  for  instance,  in  Clausilia,  while  among  those 
with  dextral  spires,  sometimes  sinistral  aberrations  are  found.  The  last  turn 
of  the  shell  is  called  the  body- whorl,  and  the  aperture  is  generally  closed  by 
an  operculum. 

The  aperture  is  either  entire,  as  in  Plate  I,  figures  10  and  21,  or  drawn  out 
or  produced  into  a  canal,  see  Plate  I,  figures  14  and  15.  Species  having  shells 
with  an  entire  aperture,  are  generally  vegetable  feeders,  whilst,  on  the  other 
hand,  the  siphonated  shells  belong  to  carnivorous  families.  The  Gasteropoda 
are  found  all  over  the  world  on  land,  in  rivers  and  fresh- water  lakes,  and  in 
the  different  oceans.  Their  fossil  representatives  run  through  all  the  different 
geological  strata,  from  the  lowest  Silurian  up  to  recent  formation  of  the 
Pliocene. 

PTEROPODA. — (Wing-footed.)  Their  locomotion  is  accomplished  by  means 
of  a  pair  of  large  fins  attached  to  the  sides  of  their  head  (see  Plate  I,  figure  4). 
Their  shells  are  univalve,  but  of  very  different  forms.  Plate  I,  figure  5,  shows 
the  fossil  shell  of  one  genera  of  Pteropoda,  a  Conularia.  Animals  of  this  class 
are  very  abundant  in  all  our  oceans,  and  furnish  food  for  a  good  many  inhabi- 
tants of  the  sea.  In  former  ages  they  lived  in  all  the  oceans  from  the  Silurian 
age  to  those  just  preceding  the  now  existing  ones. 

BRACHIOPODA. — The  Brachiopoda  are  bivalve  shell-fish,  which  differ  from 
the  ordinary  mussels,  cockles,  etc.,  in  being  always  equal  sided,  but  never 
quite  equal-valve.  Their  forms  are  symmetrical,  and  so  commonly  resemble 
antique  lamps  that  they  were  called  lampades,  or  lamp  shells,  by  the  old  natu- 
ralists. The  hole  which,  in  a  lamp,  admits  the  wick,  serves,  in  the  shell,  for 
the  passage  of  the  pedicle  by  which  it  is  attached  to  submarine  objects.  The 
valves  of  the  Brachiopoda  are  respectively  dorsal  and  ventral.  The  ventral 
valve  is  usually  the  larger,  and  has  a  prominent  beak,  by  which  it  is  attached 
or  through  which  the  organ  of  adhesion,  the  pedicle,  passes.  The  valves  are 
articulated  by  two  curved  teeth  in  the  ventral  valve,  which  are  received  by 
sockets  of  the  dorsal  valve ;  some  genera  and  species  are  not  provided  with  such 
hinges.  In  both  the  articulated  and  unarticulated  Brachiopods,  the  valves  are 
opened  and  closed  by  strong  muscles,  whose  places  of  attachment  are  seen  in 


24  PALEONTOLOGY    OF    KENTUCKY. 

Plate  I,  figure  25.  Among  the  fossil  shells  of  even  the  older  Palaeozoic  strata, 
we  find  sometimes  Brachiopod  shells  so  well  preserved  that  even  the  valves 
may  be  opened  as  far  as  the  teeth  and  sockets  of  the  hinge  will  allow.  Most 
of  the  shells  of  Brachiopods  have  a  peculiar  structure,  consisting  of  flattened 
prisms  of  considerable  length,  arranged  parallel  to  each  other  with  great  regu- 
larity, and  obliquely  to  the  surfaces  of  the  shell,  which  is  also  perforated  by 
canals  (see  Plate  I,  figure  22).  This  great  class  of  Mollusca  has  derived  its 
name  from  the  two  long  ciliated  arms  developed  from  the  sides  of  the  mouth, 
with  which  each  animal  is  provided  as  means  to  create  currents  which  bring 
to  it  its  food.  These  arms  (Plate  I,  figure  9)  were  considered  by  former  natu 
ralists  as  instruments  of  locomotion ;  but  it  is  now  ascertained  that  they,  out- 
side of  their  first  mentioned  purpose,  serve  mainly  as  breathing  organs ;  the 
erroneous  name  Brachiopoda  (arm-footed),  should,  therefore,  be  corrected  into 
Brachionabranchia  (arm-breathers).  Most  of  the  Brachiopoda  are  provided 
with  an  internal  skeleton,  consisting  of  two  spiral  processes  in  the  Spiriferirhe 
(see  Plate  I,  figures  7  and  8),  whilst  in  others,  the  Terebratula  and  Thecidin, 
this  skeleton  takes  the  form  of  a  loop,  as  seen  in  Plate  I,  figures  6  and  26. 
This  skeleton  serves  as  a  support  for  the  brachial  membrane.  The  prominent 
parts  of  the  Brachiopod  shell  are  the  following :  Dorsal  valve,  the  upper  one, 
which  is  usually  the  smaller,  ventral  valve,  the  lower  one,  which  is  generally 
the  larger.  The  beak  is  that  portion  of  the  valve  which  terminates  above  the 
hinge -line  in  a  sharp  point  or  in  a  perforation  (as  seen  in  Plate  I,  figure  25 
"a5').  This  perforation  is  called  the  foramen.  The  most  convex  portion  of 
the  valve  near  the  beak  is  known  as  the  umbo.  Most  of  the  shells  have  below 
the  beak  a  triangular  opening,  which,  in  valves  without  hinge  line,  is  closed 
by  a  separate  body,  consisting  of  either  one  or  two  pieces,  the  deltidium.  In 
shells  with  a  hinge  area,  as  the  Spirifera  and  Cyrtina,  said  area  is  divided  in 
two  by  the  triangular  opening,  which  is  partly  or  entirely  closed  by  the  growth 
of  the  shell.  This  is  known  as  the  pseudo- deltidium.  In  some  shells  the 
outline  of  the  valve  forms  on  both  sides  of  the  hinge  a  straight  line,  the  hinge 
line,  which  may  be  as  long  as  the  greatest  breadth  of  the  shell,  or  may  be  so 
short  as  scarcely  to  be  noticeable.  The  area  which  sometimes  exists  between 
hinge-line  and  beak  is  the  hinge -area,  best  developed  in  the  shells  of  Cyrtina. 
The  hinge-area  may  be  straight  or  curved,  and  is  always  divided  by  the  pseudo - 
deltidium. 

The  valves  of  a  shell  are  either  both  convex,  or  one  convex  and  the  other 
plane,  or  one  convex  and  the  other  concave.  In  some  shells,  as  in  Spirifera, 
the  ventral  valve  has  a  strong  depression  extending  and  enlarging  from  the 
beak  to  the  front,  dividing  the  valve  into  two  equal  halves.  This  depression  is 
known  as  the  mesial  sinus.  Corresponding  with  this  mesial  sinus  is  an  eleva- 
tion in  the  dorsal  valve,  extending  and  enlarging  also  from  beak  to  front,  and 


A    SKETCH    OF    GEOLOGY.  25 

called  the  mesial  fold.  Cardinal  area  is  a  synonym  for  hinge -area,  and  cardi- 
nal extremities  are  the  extreme  points  of  the  hinge-line.  Of  all  the  Mollusca, 
the  Brachiopoda  enjoy  the  greatest  range  both  of  climate  and  depth  and  time  ; 
they  are  found  in  tropical  and  polar  seas.  The  living  species  prefer  the  deep 
waters  to  shallow  lakes,  though  some  of  them  are  found  even  here.  Of  the 
population  of  the  seas  of  former  ages,  they  formed  a  very  large  part.  Their  fos- 
sil remains  are  found  in  almost  every  strata  of  the  whole  geological  column. 
They  are  not  only  very  abundant,  but  also  well  preserved,  and  form  the  princi- 
pal treasures  of  many  palaeontological  collections. 

LAMELLIBRANCHIATA. — The  Mollusca  of  this  class  are  familiar  to  every  one ; 
they  are  represented  by  the  oysters,  mussels  and  cockles.  The  animal  is 
without  head,  and  the  shell  is  bivalve.  The  valves  are  attached  to  the  sides 
of  the  animal.  We  have,  therefore,  in  this  class,  a  right  and  left  valve.  Plate 
I,  figures  3  and  20,  show  the  left  valves.  In  figure  17,  the  upper  valve  is  a  right 
one,  and  the  lower  a  left  one.  The  mouth  of  the  animal  is  generally  directed 
towards  the  shorter  slope  of  the  shell.  The  hinge  is  on  the  back  of  the  animal 
and  formed  by  teeth  and  sockets,  together  with  an  elastic  ligament.  The  shells 
are  closed  by  powerful  adductor  muscles,  but  open  when  the  animal  relaxes 
the  muscles,  or  when  it  is  dead.  We  distinguish  in  the  shells  of  this  class  the 
dorsal,  ventral,  anterior,  and  posterior  margins.  The  dorsal  margin  contains 
the  hinge,  whilst  the  ventral  margin  is  opposite  to  this.  The  anterior  margin 
forms  the  end  of  the  shell  on  the  shorter  slope,  and  the  posterior  margin  the 
end  of  the  longer  slope. 

Plate  I,  figure  3,  is  the  left  valve  of  Cytherea  dione,  separate  from  Cyth- 
erea,  with  the  following  prominent  parts :  h,  the  hinge  ligament ;  d,  the  umbo ; 
f,  the  lunule ;  c,  cardinal  tooth ;  tt,  lateral  teeth  ;  a,  anterior  adductor  muscle  ,- 
a,  posterior  adductor  muscle ;  p,  pallial  impression  ;  s,-  sinus,  occupied  by  re- 
tractor of  the  siphons.  The  line  designated  as  pallial  impression,  which  in 
many  shells  is  prominently  marked,  indicates  the  place  where  the  mantle  is 
attached  to  the  shell.  The  presence  of  a  bay  or  sinus  (s),  in  the  line  of  the 
pallial  impression,  proves  the  animal  to  have  possessed  retractile  siphons. 
All  the  Mollusca  belonging  to  this  class  live  in  the  water,  in  rivers,  lakes  and 
oceans.  They  are  abundant  at  the  present  time,  and  have  been  so  in  all  the 
seas  of  former  ages.  Their  fossil  remains  are  often  extremely  well  preserved, 
and  add  greatly  to  the  beauty  of  many  Palaeozoic  collections. 

Within  the  here  described  five  classes,  the  different  Mollusca  are  divided  into 
families,  genera  and  species.  The  naturalists  of  former  centuries  were  able  to 
give  a  more  precise  definition  of  these  terms.  They  believed  that  each  species 
was  a  priori  created,  and  thus  by  sharply  defined  lines  of  distinction,  separated 
from  all  the  other  forms,  and  only  related  to  some  of  these  by  accidental  sitni- 

GKOL.   SUR. — 4 


26  PALAEONTOLOGY    OF    KENTUCKY. 

larity  in  certain  features.  Inasmuch  as  relation  between  organic  beings 
depends  upon  their  origin  from  common  ancestors,  no  real  relation  could 
exist  outside  of  a  species  among  the  animals  and  plants,  if  the  former  belief 
in  the  stability  of  species  had  remained.  The  erroneous  views  of  the  old  school 
were  based  upon  observations  among  the  more  highly  developed  animals  and 
plants,  where  the  division  lines  between  the  species  are  more  pronounced. 

Had  the  scientists  of  olden  times  directed  their  investigation  to  the  lower 
organisms,  they  would  soon  have  met  with  difficulties,  and  in  many  cases  even 
with  impossibilities,  to  accomplish  a  specific  differentiation .  The  evolution 
theory  has  upset  the  views  of  the  old  school.  It  does  not  believe  in  a  separate 
original  creation  for  every  species,  but,  according  to  it,  new  ones  are  produced 
by  gradual  modifications  of  old  forms.  Changes  in  organisms  may  be  either 
temporary,  that  is,  dying  out  with  the  same  specimen  in  which  they  first  occur, 
or  they  may  be  constant,  when  they  reappear  in  all  the  succeeding  generations. 
Only  these  constant  alterations  will  lead  towards  new  species,  and  in  order  to 
do  this,  they  must  intensify  in  every  succeeding  specimen,  until  they  become 
so  characteristic  as  to  afford  an  easy  and  sure  distinction  between  the  original 
and  the  new  species.  It  is  obvious  that  this  procedure  in  the  creation  of 
species  will  leave  some  specimens  in  a  doubtful  position ;  their  modifications 
may  separate  them  from  the  old  forms  and  still  be  insufficient  to  place  them 
among  the  new  ones.  These  forms  are  connecting  links,  and  serve  to  establish 
a  general  relationship  in  larger  groups  of  organism ;  but  they  cause  consider- 
able trouble  as  far  as  classification  is  concerned. 

It  is  impossible  to  state  the  exact  amount  of  similarity  required  between 
two  animals  or  two  plants,  which  will  place  them  both  either  in  the  same 
family,  the  same  genus,  or  the  same  species.  In  recent  years  a  real  mania  has 
sprung  up  among  some  naturalists  to  manufacture  as  many  genera  and  species 
as  possible.  By  such  proceedings  science  is  not  benefited,  but  only  becomes 
incumbered  with  synonyms,  of  which,  sooner  or  later,  it  has  to  be  purged. 
Such  a  cleaning  process  will  be  necessary  in  Palaeontology.  This  science, 
which  has  lately  passed  its  childhood,  and  which  handled  material,  the  charac- 
ter of  which  was  little  known,  has  certainly  established  species  and  genera 
which  will  require  revision.  We  find,  for  instance,  of  some  fossil  shells  speci 
mens  showing  the  outside  shell  with  all  the  markings  well  preserved,  and 
again,  others  in  the  condition  of  internal  casts,  with  all  the  shell  exfoliated 
between  such  specimens  exist  differences  rendering  it  impossible  to  recognize 
their  intimate  relation  without  closer  investigation.  That  the  first  geologists, 
noticing  these  two  different  forms,  described  them  as  different  species,  is  quite 
natural ;  but  as  soon  as  material  of  this  kind  increased,  some  forms  were  found, 
showing  partly  the  internal  cast  and  partly  the  exterior  shell,  combining  the 
two  fossils  which  were  so  far  considered  as  different  species.  Again,  we  have 


A    SKETCH    OF    GEOLOGY.  27 

certain  species  in  which  the  extreme  forms  are  so  different  irom  each  other 
that  any  one  finding  only  these  two  extremes,  would  be  fully  justified  in  de- 
scribing them  as  different  species,  but  increased  material  furnishes  intermediate 
forms  connecting  those  extremes  into  one  species. 

Before  closing  these  introductory  remarks,  I  will  copy  from  an  English  writer 
some  observations  which  show  the  beneficial  influence  of  the  cultivation  of 
natural  sciences  upon  the  minds  and  morals  of  the  people,  words  which  should 
be  well  remembered  by  every  parent  looking  to  the  welfare  of  his  child  ;  by 
every  teacher  aiming  by  his  labors  to  ennoble  the  mind  and  character  of  his 
students ;  and  by  every  trustee  of  schools  endeavoring  to  elevate  those  institu- 
tions to  real  nurseries  of  the  highest  type  of  civilization.  He  remarks:  "It  is 
fearfully  true,  that  nine-tenths  of  the  immorality  which  pervades  the  better 
classes  of  society,  originate  from  the  want  of  an  interesting  occupation  to  fill 
up  their  vacant  time  ;  and  as  the  study  of  natural  sciences  is  as  attractive  as  it 
is  beneficial,  it  must  necessarily  exert  a  moral  and  even  religious  influence  upon 
the  young  and  inquiring  mind.  The  youth  who  is  fond  of  scientific  pursuits 
will  not  enter  into  revelry,  for  frivolous  or  vicious  excitement  will  have  no  fas- 
cinations for  him.  The  overflowing  cup,  the  unmeaning  or  dishonest  game,  will 
not  entice  him.  If  any  one  doubts  the  beneficial  influence  of  these  studies  on 
the  morals  and  character,  I  would  ask  him  to  point  out  the  immoral  young 
man  who  is  devotedly  attached  to  any  branch  of  natural  science.  I  never 
knew  such  an  one,  and  if  there  are  any,  they  are  rare  exceptions ;  and  the 
loud  clamors  which  are  always  raised  against  the  man  of  science  who  errs, 
prove  how  rarely  the  study  of  the  works  of  nature  fails  to  exert  an  ennobling 
effect  upon  a  well  regulated  mind.  Fortunate,  indeed,  are  the  youth  of  either 
sex,  who  early  imbibe  a  taste  for  natural  knowledge,  and  whose  predilections 
are  not  thwarted  by  injudicious  friends." 

These  remarks,  based  upon  indisputable  facts,  show  that  the  value  of  the 
natural  sciences  ought  not  to  be  estimated  only  by  their  financial  result, 
which  is,  unfortunately,  the  only  scale  with  which  most  people  nowadays 
measure,  but  also,  and  more  deservedly  so,  by  their  ennobling  influence  upon 
the  hearts  and  brains  of  the  human  race. 


FOSSIL  SHELLS 


OP    THE 


SILURIAN  AND  DEVONIAN  ROCKS. 


BY 


HENRY  NETTELROTH. 


II. 


DESCRIPTION  OF  SPECIES. 


OF   THE 


SILURIAN  AND  DEVONIAN  ROCKS, 


COELENTERATA. 

SPONGIA. 
Genus  Brachiospongia.    Marsh. 

Described  by  Marsh  in  Am.  Journal  of  Scie.  and  Arts.,  2d  series.  Vol.  44,  1807 — Etymology:  brachium, 

an  arm;   spongia  a  sponge. 

Brachiospongia  digitata.    OWEN 

Plate  XXXV.,  figure  3,  and  Plate  XXXVI.,  figures  1  and  3. 
Scyphia  digitata,  Owen.     First  Ky.  Geol.  Kep.,  Vol.  II.,  p.  Ill — 1857. 

This  fossil  is  very  peculiar  and  very  interesting ;  Prof.  D.  D.  Owen,  who 
described  it  in  his  Kentucky  Report,  placed  it  in  the  genus  Scyphia  of 
Schweigg,  but  its  proper  place  is  in  the  later  established  genus  Brachiospongia 
of  Marsh.  It  consists  of  a  circular  or  elliptical  central  body,  which  is  hollow, 
and  has  on  its  lower  side  an  elliptical  aperture  occupying  about  one-third 
of  the  lower  surface.  This  aperture  is  surrounded  by  an  elevated  thick  brim, 
which  rises  in  the  specimen  before  me  more  than  an  inch  and  a  quarter  above 
the  general  surface;  its  greater  diameter  measures  four  and  its  smaller  two 
inches  and  a  quarter.  From  the  circumference  of  the  central  body  radiate  in 
my  shell  twelve  large,  cylindrical,  geniculated  tubes,  while  in  fossils  seen  by 
Prof.  Owen  he  counted  only  from  eight  to  eleven.  These  tubes  start  from  the 
periphery  with  a  downward  direction  for  about  a  little  more  than  an  inch, 
where  they  make  an  abrupt  turn  of  about  ninety  degrees  upwards,  to  the  ex- 
tent of  more  than  three  inches.  If  the  interspaces  between  the  tubes  were 
closed,  the  fossil  would  form  a  medium  sized  basin  or  bowl,  with  an  elevated 
center.  The  tubes  are  all  of  about  the  same  size  and  shape  ;  all  have  an  aper- 
ture on  top,  which  is  different  in  shape  ;  in  some  the  opening  is  elliptical,  while 
in  others,  it  extends  to  the  knee ;  but  there  is  no  doubt  that,  in  original  speci- 
mens, the  aperture  was  limited  to  the  top,  and  the  lateral  enlargement  of  the 


£6  PALAEONTOLOGY    OF    KENTUCKY. 

opening  is  due  to  wear  and  rubbing  in  its  fossil  condition.  The  internal 
structure  is  destroyed,  and  only  the  outline  or  general  form  preserved.  The 
central  body  measures  six  inches  in  diameter,  while  the  circle,  formed  by  the 
tops  of  the  tubes,  has  a  diameter  of  nine  inches. 

Formation  and.  Locality. — This  interesting  fossil  is  limited  to  one  locality;  it  is  found  in  the  lower 
strata  of  the  Cincinnati  or  Hudson  Kiver  group,  at  Bright's  Mill,  on  Benson  Creek,  a  few  miles  west  of 
Frankfort,  Ky.,  where,  altogether,  not  more  than  about  a  dozen  fcir  specimens  have  been  found,  while 
ractional  specimens  are  more  numerous. 

MOLLUSCA. 

BRYOZOA. 
Genus  Ptilodictya.    Lonsdaie. 

Ptilodictya,  Lonsdaie.     Murch.  Sil.  Syst. — 1839. 
Etymology :  ptilon,  a  wing ;  dictyon,  a  net. 
The  correct  orthography  would  be  Ptilodictyon. 

Fronds  simple  or  branched,  springing  from  a  pointed  or  wedge-shaped,  sub- 
solid,  and  finely  striated  base  or  articulating  process,  which  fitted  loosely  in 
the  socket  of  the  expanded  and  firmly  attached  base.  The  free  portion  of  the 
zoarium  is  two-edged,  with  the  transverse  or  cross  section  acutely  elliptical, 
with  the  surface  either  smooth,  montiferous,  or  marked  by  transverse  ridges, 
and  composed  of  two  equal  but  distinct  sides ;  each  side  is  provided  with  a 
delicate  epithacal  membrane,  from  which  the  cells  rise  to  open  on  the  two 
opposite  faces  of  the  frond.  Cells  quadrate,  rhomboidal,  or  hexagonal,  and 
arranged  in  longitudinal  series,  or  in  a  quincuncial  manner ;  pseudo-septa  are 
frequently  present ;  the  walls  are  pierced  in  many  species  by  connecting  fora- 
mina. The  interstitial  cells  are  usually  absent ;  but  in  the  nodose  species  the 
summits  of  the  monticules  are  often  occupied  by  smaller  cells  than  the  aver- 
age. In  the  robust  species  the  tubes  are  crossed  by  diaphragms  placed  upon 
the  same  level  in  contiguous  tubes. 

Ptilodictya  hilli.    JAMES. 

Plate  XXX V.,  figures  1,  2,  4  and  5. 
Ptilodictya  hilli,  James.     Cin.  Journ.  of  Nat.  Hist.,  Vol.  V.,  pt.  3,  plate  7,  figure  7.,  no  descpt. — 1882. 

Zoarium  digitate,  the  number  of  prongs  not  known  ;  the  specimen  before  me 
shows  one  complete  branch,  which  deflects  from  the  original  stem,  just  above 
the  wedge-shaped  articulating  process,  out  of  the  sharp  edge,  and  extending 
in  the  same  plane  with  the  main  stem.  On  one  of  the  broad  sides  of  the 
main  stem,  and  in  its  center  line,  are  two  protuberances,  the  one  opposite 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  a  I 

the  center  line  of  the  deflecting  branch,  and  the  other  about  one-fourth  of 
an  inch  above  it,  which  appear  to  be  the  buds  of  two  new  branches,  but 
whose  positions  make  it  somewhat  doubtful,  inasmuch  as  those  new  stems 
would  leave  the  plane  of  the  two  existing  prongs.  In  similar  species,  as 
P.  ramosa  and  P.  briareus,  the  branches  start  always  from  the  sharp  edge, 
and  I  do  not  doubt  that  the  same  is  the  case  with  P.  hilli.  We  may, 
therefore,  assume,  that  very  few  branches  are  formed.  This  species  is  gen- 
erally found  in  more  or  less  straight,  thin  strips,  of  different  width,  the 
cross  sections  of  which  are  either  acutely  elliptical  or  elliptic-lanceolate.  Both 
sides  are  entirely  equal;  they  are  most  convex  in  their  central  line,  from  where 
they  slope  in  a  regular  but  gentle  curve  to  the  lateral  margins,  where  the  sur- 
faces of  both  sides  meet  at  a  very  acute  angle.  The  surfaces  of  both  sides  are 
covered  by  transverse,  sharply  angular  ridges,  with  interspaces  of  about  twice 
their  own  width.  Some  of  these  plications  cross  the  branches  from  one  edge 
to  the  other  in  a  straight  line,  rectangular  with  the  margin,  the  course  of 
others  is  somewhat  oblique,  and  others  again  cross  the  surface  only  partly. 
These  shorter  ribs  are  always  intercalated,  and  never  produced  by  bifurcation. 
The  whole  zoarium  is  covered  by  closely  arranged  rhomboidal  cells  of  about 
equal  size,  the  walls  of  which  form  nearly  straight  lines,  crossing  each  other 
obliquely.  The  largest  specimen  in  my  possession  measures  nearly  four 
inches  in  length,  -by  more  than  an  inch  in  width  ;  in  its  whole  extent  it  does 
not  show  any  branch  ;  it  has  thirteen  transverse  ribs  in  the  space  of  an  inch. 
A  smaller  specimen  measures  one  inch  and  three- eighths  in  length,  by  one- 
fourth  of  an  inch  in  width,  with  nineteen  cross  ribs  in  the  space  of  an  inch. 

Formation  and  Locality.— This  species  is  named  after  Dr.  O.  O.  Hill,  formerly  of  Cincinnati,  Ohio, 
who  first  discovered  it.  It  was  afterwards  found  rather  abundantly  in  the  upper  strata  of  the  Hudson 
Kiver  group  at  Danville,  Ky.,  by  Prof.  Linney,  of  the  Kentucky  Geological  Survey. 


MOLLUSCA. 
BRACHIOPODA. 
Genus  Crania.    KetziU8. 

Crania.      Ketzius.    Schrift  der  Berliner  Gesellschaffc  Nat.  Freunde.    1781.   Etymology:  Kranion 

the  upper  part  of  the  skull. 

Shell  smooth  or  -striated  by  radiating  striae  ;  umbo  of  the  dorsal  valve  sub- 
central  ;  umbo  of  the  ventral  valve  sub-central,  marginal  or  prominent  and 
cap-like,  with  an  obscure  triangular  area  traversed  by  a  central  line.  Shell 
usually  attached  to  other  shells  or  marine  bodies.  The  large  muscular  impres,- 


32  PALAEONTOLOGY    OF    KENTUCKY. 

sions  of  the  attached  valve  are  sometimes  convex,  in  other  species,  deeply 
excavated  ;  those  of  the  upper  valve  are  usually  convex.  In  C.  tripartita  of 
Minister,  the  nasal  process  divides  the  fixed  valve  into  three  cells.  Some  of 
the  species  are  either  entirely  free  or  but  slightly  attached.  Crania  craniolaris 
is  the  type  of  the  genus,  which  extends  from  the  Lower  Silurian  to  the  present 
day. 

Crania  bordeni.      HALL  AND  WHITFIKLD. 

Plate  II.,  Pig.  14. 

Crania  bordeni,  H.  &  W.     24th  Regent's  Report,  p.  187—1872. 
Crania  bordeni,  H.  &  W.     27th  Regent's  Report,  pi.  9—1875. 

Shell  depressed  conical,  about  half  as  high  as  wide ;  beak  sub-central, 
slightly  nearer  the  anterior  end.  Surface  marked  by  fine  radiating  striae, 
and  somewhat  strong  lines  of  growth,  giving  a  rugose  character  to  surface, 
especially  toward  the  margin.  This  species  resembles  Crania  crenistria,  from 
the  Hamilton  group  of  New  York,  but  that  species  is  more  coarsely  striated 
than  our  shell. 

Formation  and  Locality.  Found  in  the  rotten  hornstone  and  in  the  cherty  layers  on  top  of  the 
hydraulic  limestone  of  the  Devonian  formation  in  Jefferson  county,  Kentucky,  and  in  Clark  county,  In- 
diana. The  quarries  for  hydraulic  cement  rock  at  Watson's  Station,  on  the  Ohio  and  Mississippi  Railroad, 
furnished  the  fine  specimen  of  Modiomorpha  concentrica,  to  which  two  fine  individuals  of  Crania  bordeni 
are  attached. 


Genus  Discina. 


Lamarck. 


Lamarck.     Hist.  Nat.   des  Animaux  sans  vertebres.  1819.  Etymology:   discus,  a  flat 
round    plate;  the  termination  inui  implying  resemblance. 

The  following  are  some  of  the  exterior  characters  of  the  shells  of  this  genus, 
as  given  by  Mr.  Davidson:  "Circular,  longitudinally  and  transversely  oval. 
Upper  or  dorsal  valve  conical,  patelliform,  with  apex  inclining  towards  the 
anterior  margin.  Lower  or  ventral  valve  opercular,  flat  or  partly  convex,  and 
perforated  by  a  narrow  oval  longitudinal  slit,  reaching  to  near  the  posterior 
margin,  and  placed  in  the  middle  of  an  oval  depressed  disk.  Surface  smooth, 
ornamented  by  numerous  striae,  radiating  from  the  apex  to  the  margin,  or  by 
concentric  lines  of  growth  produced  in  foliaceous  expansions.  Shell  structure 
horny,  and  perforated  by  minute  tubuli." 

Discina  doria.    HALL. 

Discina  doria,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  page  19—1867. 

Shell  very  small,  sub-circular  or  oblate,  the  transverse  diameter  usually  the 
greater,  but  in  some  specimens  it  is  reverse.  Dorsal  valve  moderately  convex, 


FOSSILS    OP    THE    SILURIAN    AND    DEVONIAN    BOOKS.  33 

apex  elevated  sub-terminal.  Ventral  valve  flat  or  concave,  the  apex  excentric  ; 
foramen  comparatively  large,  oval,  with  margins  depressed.  The  shell  itself  is 
very  thin. 

The  surface  is  marked  by  fine,  closely  arranged  concentric  striae,  which  are 
plainly  visible  on  our  specimens,  though  they  are  internal  casts,  and  entirely 
silicified. 

This  species  closely  resembles  the  D.  newberry,  from  Cuyahoga  Falls,  Ohio; 
but  that  shell  is  somewhat  thicker  and  stronger,  with  the  apex  of  the  dorsal 
valve  more  elevated,  and  the  shell  is  altogether  larger  than  our  specimens. 
One  of  the  specimens  before  me  measures  three  lines  and  a  half  in  length,  by 
three  lines  in  width,  and  its  elevation  about  one  line. 

Formation  and  Locality. — The  specimens  of  this  species  are  adhering  to  other  fossils,  a  fact  which 
would  make  their  identity  with  Discina  doubtful,  if  not  both  valves  were  found  so  attached.  The  speci- 
men* before  me,  three  in  number,  occupy  the  valve  of  a  Spir.  oweni,  and  were  found  in  the  Devonian  rocks 
of  Clark  county,  Indiana. 

Discina  grandis.    VANUXEM. 

Plate  III.,  Figure  3. 

Orbicula  grandis,  Vanuxem.      Geol.  Kep.  3d  dist — 1842. 
Discinv  grandis,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  7—1867, 
Discina  grandis,  H.  &  W.     24th  Reg.  Eeport,  p.  187—1872. 
Discina  grandis,  H.  &  W.     27th  Keg.  Rep.,  pi.  9—1875. 

General  form  broadly  and  transversely  elliptical ;  either  plano-convex  or 
concavo-convex.  Dorsal  valve  sometimes  extremely  elevated  ;  apex  sub-central, 
a  little  on  one  side  of  the  transverse  axis.  Ventral  valve  usually  moderately 
concave ;  foramen  reaching  from  the  center  or  near  the  center  towards  one  side, 
but  varying  somewhat  in  different  individuals.  Surface  is  marked  by  fine  con- 
centric striae,  crowded  near  the  center,  and  more  distant  and  sharply  elevated 
towards  the  margin.  This  species  is  easily  recognized  by  its  larger  size,  and 
in  the  ventral  valve  by  the  direction  of  the  foramen  being  in  the  shorter  diam- 
eter of  the  shell.  This  valve  is  somewhat  unequally  concave,  and,  on  the  side 
of  the  foramen,  often  a  little  convex.  The  specimen  here  described  and  figured, 
has  diameters  of  fourteen  and  twelve  lines,  and  a  height  of  six  lines  and  one- 
half,  it  may  be  considered  as  of  average  size  among  the  shells  found  here. 

Formation  and  Locality.  This  species  is  often  met  with  in  our  rocks,  but  only  the  dorsal  valve  Is 
preserved,  it  is  always  entirely  silicified,  and  occurs  in  the  cherty  layers,  superimposed  upon  the  hydraulic 
limestone  of  the  Devonian  formation,  in  Jefferson  county,  Kentucky,  and  in  Clark  county,  Indiana.  All 
my  specimensof  this  species  I  found  in  the  cement  quarries  at  Watson's  Station,  on  the  Ohio  and  Missis- 
sippi Railroad,  where  the  chert  beds  come  near  the  surface. 
GEOL.  SUB. — 5 


34  PALAEONTOLOGY    OF    KENTUCKY. 


Brugmere. 
Bruguiere.    Encycl.  Meth.—  1792.    Etymology  :  lingula,  a  little  tongue. 

Shell  oblong,  compressed,  sub-equivalve,  attached  by  a  pedicle  passing  out 
between  the  valves.  Shell  structure  minutely  tubular,  texture  horny.  Shell 
slightly  gaping  at  each  end,  truncated  in  front,  rather  pointed  at  the  um- 
bones  ;  dorsal  valve  rather  shorter,  with  a  thickened  hinge-margin  and  a  raised 
central  ridge  inside.  (Woodward.) 

Lingula  triangulata.     n.  sp. 

Plate  XXVI.,  Figure  1. 

Shell  of  medium  size  ;  sub-triangular  or  broadly  sub-ovate.  The  lateral 
margins  form,  at  the  apex,  an  angle  of  about  sixty  degrees  ;  the  sides  slope 
from  apex  to  two-thirds  of  the  length  of  shell  in  a  straight  line  ;  from  there 
they  curve  gently  to  basal  margin,  which  is  broadly  rounded.  Shell  is  mod- 
erately convex  from  beak  down  to  front,  but  depressed  almost  flat  at  margins. 
The  greatest  width  is  about  one-third  of  length  of  shell  from  the  front  ;  width 
is  smaller  than  length.  The  specimen  before  me  measures  twelve  lines  in 
length  by  ten  lines  in  width.  Shell  itself  is  thick.  The  surface  is  marked  by 
fine  concentric  lines  of  growth,  and  also  by  fine  radiating  striae,  both  of  which 
are  somewhat  obscure  on  account  of  exfoliated  condition  of  fossils,  which  are 
mostly  internal  casts.  It  appears  to  have  some  resemblance  with  Lingula 
paliformis  of  the  Hamilton  group,  but  differs  from  it  by  its  shape  and  sur- 
face-markings. 

Formation  and  Locality.  Found  in  the  Hydraulic  limestone  of  the  Devonian  formation  at  the  Falls 
of  the  Ohio,  in  Kentucky. 

GenUS    OrtMS.       Dalman. 

Orthis,  Dalman.     Kongl.  Vet.  Acad.  Handl.—  1817. 

Etymology:  Orthis,  straight,  in  allusion  to  the  straight  hinge  line. 

Shell  variable  in  shape,  sub-  circular  or  quadrate  ;  valves  equally  or  unequally 
convex,  socket  valve  sometimes  slightly  concave,  with  or  without  a  mesial  fold 
or  sinus  ;  hinge  line  straight,  generally  shorter  than  width  of  shell.  Both 
valves  furnished  with  an  area,  divided  by  an  open,  triangular  fissure  for  pas- 
sage of  the  pedicle.  Beaks  more  or  less  incurved,  that  of  larger  valve  gener- 
ally more  produced.  Surface  smooth,  striated,  or  ornamented  by  single, 
bifurcated,  or  intercalated  ribs.  Structure  minutely  or  largely  punctate. 
Valves  articulating  by  means  of  teeth  and  sockets. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  35 

In  interior  of  ventral  valve  the  vertical  dental  plates  form  the  walls  of 
the  fissure,  and  extend  from  beak  to  bottom  of  shell ;  between  these  a  small 
rounded  mesial  ridge  divides  the  'muscular  scars,  which  extend  over  two  elon- 
gated depressions,  margined  on  their  outer  side  by  the  prolonged  bases  of  the 
dental  plates.  The  cardinal  muscles  appear  to  have  occupied  greater  portion 
of  anterior  division  of  these  two  depressions ;  the  pedicle  muscles  occupying 
the  external  and  posterior  part  of  same  space. 

The  adductor  was  probably  attached  to  each  side  and  close  to  mesial  ridge. 
In  the  socket  valve  the  fissure  is  partly  or  entirely  occupied  by  a  more  or 
less  produced  simple  shelly  process,  to  which  were  affixed  the  cardinal  muscular 
fibres,  the  inner  socket  walls  are  considerably  prolonged  into  cavity  of  the 
shell,  under  shape  of  projecting  laminae,  to  the  extremity  of  which  free,  fleshy, 
spiral  arms  may,  perhaps,  have  been  affixed.  Under  this  shelly  process  a 
longitudinal  ridge  separates  the  quadruple  impressions  of  the  adductor,  which 
on  each  side  forms  two  deep  oval  depressions,  placed  obliquely  one  above  the 
other,  and  separated  by  lateral  ridges,  branching  from  the  center  one.  The 
genus  Orthis  is  very  nearly  related  to  Strophomena,  from  which  the  more 
typical  forms  may  in  general  be  easily  separated  by  their  usually  greater  con- 
vexity, and  the  rounder  and  shorter  hinge-line. 

Orthis  biforata.    Schiotheim. 

Plate  XXIX.,  figures  18  to  22. 

Terebratulites  biforatus,  Schiotheim,  Petrefact.     P.  265 — 1820 
Orthis  biforata,  Meek.     Pal.  of  Ohio,  Vol.  I.,  p.  112—1873. 
See  the  list  of  synonyms  in  last  cited  Report. 

Shell  small,  transversely  oval-subquadrate,  moderately  convex,  wider  than 
long ;  hinge-line  a  little  less  than  the  greatest  width  of  the  shell ;  cardinal 
angles  obtuse,  seldom  rounded.  Surface  plicate. 

Ventral  valve  depressed  convex  ;  mesial  sinus  well  defined  from  beak  to 
front,  deep,  with  flattened  bottom,  containing  four  plications,  the  central  ones 
starting  from  the  beak,  while  the  lateral  start  about  the  middle  of  valve  from 
marginal  slopes  of  the  sinus. 

In  one  of  my  specimens  one  of  the  lateral  plications  within  the  sinus  is 
wanting;  beak  a  little  more  elevated,  and  somewhat  stronger  than  that  of 
the  opposite  valve,  only  faintly  curved,  almost  straight ;  cardinal  area  narrow, 
but  increasing  in  height  towards  beak ;  foramen  almost  an  equilateral  tri- 
angle. 

Dorsal  valve  generally  a  little  more  convex  than  other,  greatest  convexity 
at  the  umbo,  from  where  it  curves  gently  and  regularly  to  lateral  and  front 
margins. 


36  PALAEONTOLOGY    OF    KENTUCKY. 

Mesial  fold  prominent  and  well-defined  from  beak  to  front,  somewhat  flat- 
tened on  top,  bearing  five  plications  in  its  lower  half.  In  younger  specimens 
the  fold  has  only  three  plications,  of  which  in  older  individuals  the  lateral  ones 
dichostomize  at  about  the  middle  of  shell,  and  thus  form  the  five  costae  of 
the  lower  part.  The  umbo  is  more,  and  the  beak  less  prominent  than  that  of 
the  other  valve;  hinge-area  also  somewhat  smaller  than  the  ventral.  Size  of 
shell  variable,  the  largest  specimen  in  my  collection,  figured  on  plate  XXIX., 
sub-figures  18,  19  and  20,  has  a  width  of  seven-eighths  of  an  inch,  a  length  of 
five-eighths  of  an  inch,  by  a  depth  of  three-eighths  of  an  inch. 

Surface  marked  by  from  five  to  seven  strong  angular  plications,  counted  at 
the  margins,  some  of  which  are  formed  by  bifurcation.  No  other  surface-mark- 
ings are  visible. 

Formation  and  Locality. — Pound  in  the  lower  strata  of  the  Niagara  formation  in  the  quarries  east  of 
Louisville,  Ky.  This  species  is  very  common  and  of  larger  forms  in  the  Lower  Silurian,  but  to  find  its 
representatives  in  the  Niagara  rocks  is  somewhat  of  a  surprise.  They  are  rather  belated  stragglers. 

Orthis  borealis.    BILLINGS. 

Plate  XXXIV.,  figures  14  to  20. 

Orthis  borealis.  Billings.     Can.  Nat.,  Vol.  IV.,  p.  436—1859. 
Orthis  frankfortensis,  James.    Cat.  Low.  Sill.  Foss.,  Gin.  gr.,  p.  10 — 1871. 
Orthis  borealis,  Meek.   Pal.  of  Ohio,  Vol.  I,  p.  101.,  pi.  8—1873 

Shell  of  rather  less  than  medium  size,  transversely  oval-sub-quadrate,  or 
truncato-sub-oval,  the  length  and  breadth  varying  with  relation  to  each  other 
from  9  to  11,  to  11  to  12 ;  both  valves  convex ;  hinge-line  generally  less  than 
the  greatest  width  of  the  shell,  and  meeting  the  lateral  margins  under  a  more 
or  less  obtuse  angle ;  lateral  margins,  from  cardinal  extremities  to  base,  form- 
ing a  compound,  reversed  curve  of  regular  form,  concave  at  the  cardinal  angles 
and  thence  convex  to  base,  which  is  broadly  rounded,  but  sometimes  showing 
also  a  faint  sinuosity.  Ventral  valve  most  convex  near  umbo,  sloping  from 
there  somewhat  abruptly,  but  in  a  gentle  curve  to  posteriolateral  margins,  while 
the  anterior  central  region  is  depressed  so  as  to  form  a  broad,  very  shallow 
mesial  sinus  which  extends  backwards  to  middle  of  shell ;  beak  more  prominent 
than  that  of  the  other  valve,  sharply  pointed,  inclined  backward  and  slightly 
arched ;  cardinal  area  broad-triangular,  well  defined  by  angular  margins,  and 
concave ;  foramen  rather  narrow,  its  height  exceeding  its  base.  Dorsal  valve 
sometimes  more  convex  than  the  other;  its  greatest  convexity  a  little  above 
the  middle  of  the  valve,  from  where  it  slopes  in  gentle  curves  to  lateral  and 
antwior  margins  ;  the  central-anterior  portion  of  the  valve  is  slightly  elevated, 
forming  a  broad,  low,  and  undefined  mesial  fold,  whose  starting  point  is  at,  or 
somewhat  in  front  of  middle  of  valve ;  beak  of  medium  size,  arched,  but  not 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  37 

incurved;  cardinal  area  of  about  half  the  height  of  the  ventral,  and  slightly 
curved.  Surface  of  both  valves  ornamented  by  distinct,  rather  prominent, 
radiating  ribs,  of  which  from  thirty-six  to  forty-four  may  be  counted  on  the 
margins  of  shell,  most  all  of  which  extend  from  beak  to  front,  Bifurcation 
is  very  seldom  noticed,  and  then  only  in  old  and  very  large  specimens.  With 
the  exception  of  a  few  imbricating  lines  of  growth,  no  other  surface-markings 
are  visible.  This  species  resembles  Orthis  plicatella,  but  is  more  convex,  and 
has  more  numerous  and  smaller  costae ;  it  is  also  less  transverse,  and  its  mesial 
depression  and  elevation  are  more  marked. 

Formation  and  Locality. — Found  at  Frankfort,  Ky.,  in  the  Trenton  limestone,  in  great  abundance, 
and  in  excellently  preserved  specimens. 


Orthis  elegant ula.    DALMAN. 

Plate  XXXII.,  figures  62  to  57. 

Orthis  elegantula,  Dalman.    K.  Vet.  Acad.  Handl.,  p.  117 — 1827. 
Orthis  canalis,  Sowerby.    Murch.  Sil.  Syst..  p.  631 — 1839. 
Orthis  canalis,  Hall.    Geol.  Rep.  4th  dist.  N.  Y.,  p.  107—1843. 
Orthis  elegantula,  Hall.    Pal.  N.  Y.,  Vol.  III.,  p.  252—1852. 
Orthis  elegantula,  Hall,    llth  Kep.  of  Indiana,  p.  285—1881. 

Shell  small,  semi- oval,  plano-convex,  sometimes  even  somewhat  concavo- 
convex  ;  length  usually  exceeding  width.  Hinge-line  less  than  greatest  width 
of  shell,  cardinal  extremities  rounded. 

Ventral  valve  gibbous,  greatest  convexity  about  the  middle  of  the  valve, 
from  where  it  slopes  in  regular  curves  gently  to  front,  more  abruptly  to  lateral 
margins,  umbo  prominent,  beak  narrow,  elevated  and  incurved  over  cardinal 
area,  which  latter  is  depressed  triangular,  not  reaching  to  cardinal  extremities; 
foramen  of  medium  size,  its  base  to  height  as  two  to  three ;  in  the  center  of 
the  valve  is  sometimes  a  slight  linear  elevation,  which  extends  from  beak  to 
front,  visible  ;  lateral  margins  regularly  but  gently  curved ;  anterior  margin 
forms  a  regular  semi-circle,  seldom  showing  in  its  center  a  slight  sinuosity. 
Dorsal  valve  either  flat  or  even  a  little  concave,  rarely  being  slightly  convex, 
often  showing  a  gentle  linear  depression  in  the  center  line  of  the  valve  from 
beak  to  front ;  hinge-area  narrow,  almost  linear  ;  beak  small  and  incurved. 
Surface  marked  by  fine  radiating  striae,  which  increase  towards  the  margins 
by  bifurcation  ;  the  lateral  ones  are  strongly  curved  outwards.  This  beautiful 
species  is  closely  allied  to  Orthis  testudinaria,  and,  perhaps,  more  nearly  to 
O.  parva,  both  of  which  are  Lower  Silurian  fossils.  In  our  specimens  the 
shell  is  generally  more  elongated,  and  the  beak  more  extended,  while  the  sur- 
face is  more  finely  striated.  Orthis  elegantula  is  easily  distinguished.  In 


38  PALAEONTOLOGY    OF    KENTUCKY. 

regard  to  size,   it  is  impossible  to  give  any  dimensions,  inasmuch  as  we  find 
the  shells  from  the  size  of  a  small  pea  to  that  of  an  average  hazelnut. 

Formation  and  Locality. — This  elegant  shell  is  found  abundantly  and  well  preserved  in  the  Niagara 
rocks  east  of  the  city  of  Louisville,  where  it,  however,  occurs  of  very  small  size;  the  specimen  represented 
on  plate  XXXII.  is  about  the  largest  individual  ever  found.  At  Waldron,  Indiana,  it  has  attained  its 
largest  size.  Average  specimens  from  there  measure  about  five-eighths  of  an  inch  in  width,  and  some- 
what more  in  length. 

Orthis  flabellum.     SOWERBY. 

Plate  XXXIV.,  figure  30. 

Orthis  flabellum,  Hall.    Kep.  4th  Geol.  Dist.— 1843. 
Orthis  flabellum,  Sowerby.    Murch.  Sil.  Syst.,  p.  639 — 1839. 
Orthis  flabellum,  Var  ?  Hall.    Pal.  N.  Y.,  Vol.  II.,  p.  254—1852. 

Shell  of  medium  size ;  semi-oval  or  semi-elliptical ;  hinge-line  equal  to 
greatest  width  of  shell ;  cardinal  angles  rectangular  or  slightly  acute ;  lateral 
margins  sometimes  slightly  contracted  below  extremities ;  balance  of  the 
lateral  margins  and  base  form  a  regular  curve ;  shell  plano-convex.  Ventral 
valve  depressed  convex,  almost  flat.  The  shell  before  me  has,  in  its  central 
line,  a  gentle  depression,  beginning  at  about  one- third  of  whole  length  of 
shell  from  base,  and  extending  to  front,  forming  a  kind  of  mesial  sinus,  but 
I  am  not  able  to  find  out  with  certainty  whether  this  sinus  is  really  a  natural 
character  of  shell,  or  whether  it  is  the  result  of  distortion.  I  am  inclined  to 
take  it  for  a  real  sinus,  inasmuch  as  balance  of  shell  does  not  show  any  signs 
of  having  been  subjected  to  any  violence.  The  dorsal  valve  is  moderately 
convex  in  its  marginal  portion,  but  almost  flat  in  its  central  part  or  in  the 
nmbonal  region. 

The  cardinal  extremities  are  slightly  deflected,  incurving  the  surface  between 
them  and  the  umbo  somewhat.  The  cardinal  area  of  the  ventral  valve  is  of 
moderate  size,  forming  a  low  triangle ;  it  is  divided  by  a  triangular  fissure, 
partly  closed  ;  the  area  of  the  dorsal  valve  is  narrow,  almost  linear  ;  the  dorsal 
beak  incurves  into  ventral  foramen. 

The  surface  of  the  shell  is  ornamented  by  about  twenty-four  to  thirty  simple, 
prominent,  sub-angular  radii,  which  increase  in  number  by  interpolation. 
These  radii  are  crossed  by  several  marked,  concentric  lines  of  growth,  which 
divide  the  surface  in  several  concentric  zones,  and  give  the  shell,  wherever  they 
become  crowded,  which  is  mostly  the  case  at  the  margins,  a  rugose  appear- 
ance. 

Formation  and  Locality. — The  only  specimen  which  I  ever  have  seen,  and  which  belongs  to  my 
own  collection,  I  found  in  the  strippings  of  one  of  the  quarries  east  of  the  city  of  Louisville;  it  was 
surrounded  by  Niagara  clay,  and  belongs  undoubtedly  to  the  Upper  Silurian  formation. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  39 

Orthis  goodwini.    N-SP- 

Plate  XVII.,  figures  30,  31  and  32. 

Shell  small,  sub-circular  or  sub-quadrate  ;  moderately  convex  in  both  valves  ; 
hinge-line  short,  equal  or  less  than  half  width  of  shell ;  cardinal  extremities 
rounded  ;  lateral  margins  almost  straight,  or  very  slightly  curved;  they  diverge 
towards  base,  in  consequence  of  which  greatest  width  of  the  shell  is  close  to 
base  or  front;  the  basal  margin  is  broadly  curved,  with  its  central  portion 
either  straight  or  slightly  inflected. 

Ventral  valve  is  somewhat  more  convex  in  its  umbonal  region  than  dorsal, 
but  in  its  basal  half  it  is  the  reverse.  Its  greatest  convexity  is  just  below 
umbo,  from  where  it  slopes  in  a  very  gentle  curve  to  lateral  and  basal  margins, 
but  more  rapidly,  even  almost  abruptly,  to  the  cardinal  lines  ;  umbo  moderate, 
beak  a  little  elevated  above  opposite  valve,  sharp- pointed  and  slightly  arched, 
but  not  incurved.  Cardinal  area  short,  but  comparatively  high,  limited  by 
sharp  margins,  and  divided  by  an  open,  triangular  foramen,  which  is  partly 
closed  at  its  base  by  the  cardinal  process  of  the  dorsal  valve. 

Dorsal  valve  moderately  convex ;  point  of  greatest  convexity  a  little  above 
middle  of  valve,  from  where  it  slopes  in  a  gentle  curve  to  all  the  •  margins  and 
to  the  beak,  giving  the  valve  over  its  whole  surface  an  even  convexity,  with 
the  exception  of  a  narrow  strip  in  the  middle,  which  extends  from  beak  to 
base,  and  which  is  slightly  depressed.  This  mesial  depression  is  deepest  in  its 
middle  portion;  it  is  only  faintly  marked  upon  the  umbo,  and  it  becomes 
shallower  but  wider  towards  the  base.  The  surface  of  both  valves  is  orna- 
mented by  fine,  thread-like  radiating  striae,  which  increase  in  number,  partly 
by  bifurcation,  but  mostly  by  intercalation ;  these  radii  are  crossed  by  several 
concentric  lines  of  growth,  which  become  more  numerous  towards  basal  mar- 
gin. In  regard  to  size,  the  specimen  illustrated  on  plate  17,  figures  30,  31  and 
32,  is  of  about  the  average  size,  though  a  few  specimens  have  been  found  which 
are  considerably  larger. 

Formation  and  Locality. — Pound  mostly  in  the  rotten  hornstone  in  upper  strata  of  the  Devonian 
formation  at  the  Falls  of  the  Ohio.  This  species  I  name  in  honor  of  Prof.  A.  C.  Goodwin,  formerly  of 
Charlestown,  Indians,  an  ardent  collector. 

Orthis  hybrida.    SOWKBBY. 

Plate  XXXII.,  figures  32  to  35. 

Orthis  hybrida,  Sowerby.     Murch.  Sil.  Syst.,  p.  630—1839. 
Orthis  hybrida,  Hall.    Geol.  Kep.  4th  dist.,  page  107—1843. 
Orthis  hybrida,  Hall.    Pal.  N.  Y.,  Vol.  III.,  p.  253—1852. 
Orthis  hybrida,  Hall,    llth  Rep.  of  Indiana,  p.  284—1881. 

Shell  small,  lenticular  or  depressed  spheroidal,  wider  than  long,  valves  nearly 


40  PALAEONTOLOGY    OF    KENTUCKY. 

equal ;  the  ventral  one  depressed  from  center  to  base,  while  the  other  one  is 
regularly  convex  ;  beak  a  little  elevated  above  the  other  and  slightly  incurved  ; 
hinge-line  much  shorter  than  width  of  shell ;  cardinal  extremities  rounded ; 
hinge-area  small.  Dorsal  valve  slightly  convex  ;  beak  and  hinge  area  small. 

Surface  covered  by  fine  radiating  striae,  which  increase  towards  the  front 
by  interpolation  and  bifurcation.  The  interpolated  striae  start  at  anterior  part 
of  umbo,  the  bifurcation  commences  at  the  middle  of  the  valves ;  sometimes 
the  bifurcation  is  repeated  or  double  ;  concentric  lines  of  growth  divide  the 
surface  of  each  valve  into  different  concentric  zones,  which  are  more  promi- 
nent in  younger  than  older  individuals.  In  young  shells  the  shape  is  more 
ovate,  in  old  ones  more  circular,  besides  the  smaller  specimens  are  more  gib- 
bous than  the  large  ones. 

This  species  is  as  variable  in  size  as  Orthis  elegantula ;  it  ranges  from  the 
size  of  a  pea  to  that  of  a  silver  half-dime  and  more. 

Formation  and  Locality. — Niagara  group  east  of  the  city  of  Louisville,  Ky.,  where  very  perfect, 
but  also  rery  small  specimens  are  pretty  abundantly  found.  The  largest  shells  of  this  species  are  found 
at  Waldron,  Indiana.  The  individual  represented  on  plate  XXXII.  is  of  the  average  size  found  near 
Louisville. 

Orthis  livia.      BILLINGS. 

Plate  XVI.,  figures  23  and  24;  Plate  XVII.,  figures  33,  34  and  35. 
Orthis  livia,  Billings.     Can.  Jour,  of  Ind.  Sci.  and  Art,  No.  27 — 1860, 
Orthis  livia,  Billings.     Can.  Jour.,  Vol.  5,  p.  267 — 1860. 
Orthis  livia,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  page  38—1867. 
Orthis  livia,  Billings.     Pal.  Fossils,  Vol.  II.,  pt.  I.,  p.  32—1874. 

This  species  w;is  established  and  first  described  by  Mr.  Billings,  of  the 
Canadian  Geological  Survey.  I  will,  therefore,  only  copy  his  description;  his 
figures  correctly  agree  with  mine. 

"Shell  sub-orbicular  or  sub-quadrate;  length  about  eight-ninths  of  the 
width ;  greatest  width  usually  a  little  in  front  of  the  middle  ;  length  of 
hinge-line  one-half  to  two-thirds  the  width  of  shell;  cardinal  extremities 
rounded ;  sides  in  most  specimens  somewhat  straight,  often  sufficiently 
curved  to  give  a  circular  aspect  to  shell ;  front  angles  obtusely  rounded ; 
front  margin  in  general  broadly  convex,  sometimes,  in  a  small  central  por- 
tion, nearly  straight.  Dorsal  valve  of  medium  convexity,  most  elevated  about 
the  middle;  the  outline  forming  an  uniform  arch  from  depressed  beak  to 
front  margin ;  slope  from  umbo  to  cardinal  angles  gently  concave ;  sometimes 
a  barely  perceptible  mesial  depression,  commencing  in  a  point  at  the  beak, 
and  becoming  obsolete  at  one-half  or  two-thirds  the  length ;  area  small,  lying 
in  plane  of  the  lateral  margins;  beak  minute,  forming  a  small  triangular 
projection,  rising  scarcely  one-fourth  of  a  line  above  edge  of  area.  Ventral 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  41 

valve  moderately  convex,  most  elevated  at  between  one-fourth  and  one-third 
the  length  from  beak,  thence  descending  with  a  flat  or  gently  convex  slope  to 
the  lateral  margins,  with  a  somewhat  concave  one  to  the  front,  and  also  to 
hinge-line  and  cardinal  angles.  The  concavity  towards  the  front  is  not  found 
in  all  specimens ;  some  shells  have  basal  portion  either  flat  or  slightly  convex. 
The  ventral  umbo  is  small  and  neatly  defined ;  beak  small,  pointed,  and  some- 
what incurved,  but  scarcely  overhanging  edge  of  area ;  area  triangular  and 
somewhat  larger  than  the  dorsal  one.  Foramen  not  observed.  Surface  covered 
with  small  sub-angular  radiating  ridges  or  striae,  of  nearly  uniform  size,  from 
eight  to  ten  in  the  width  of  three  lines,  increasing  by  bifurcation,  strongly 
curved  outwards  on  lateral  parts  of  shell ;  the  interspaces  sub- angular  and 
equal  in  size  with  the  striae. 

"In  very  perfect  specimens  very  fine  concentric,  sub-lamellar  striae  are  visible, 
seven  or  eight  to  one  line.  In  certain  conditions  of  preservation,  also,  the 
radiating  striae  are  seen  to  be  sub-tubular,  and  exhibit  numerous  small  oval 
or  circular  openings  on  their  edges,  each  about  the  eighth  or  tenth  of  a  line  in 
width,  and  from  one-fourth  to  two- thirds  of  a  line  distant  from  each  other." 
(Billings.)  The  largest  specimen  which  I  have  seen  of  this  species  is  the  one 
illustrated  on  plate  16,  figures  23  and  24,  though,  according  to  Mr.  Billings' 
statement,  this  species  attains  in  some  specimens  a  considerably  larger  size. 

This  species  is  allied  to  Orthis  vanuxemi,  but  is  more  coarsely  striated. 

Formation  and  Locality. — Found  in  the  rotton  hornstone  in  the  upper  strata  of  the  Devonian 
formation,  in  Jefferson  county,  Kentucky,  and  in  Clark  county,  Indiana.  It  is  rarely  found  in  specimens 
of  the  size  as  shown  in  the  illustration,  while  smaller  shells,  like  those  figured  plate  17,  figures  33,  34  and 
35,  are  not  so  rare;  with  these  latter  there  is,  however,  the  trouble  to  distinguish  them  from  smaller 
specimens  of  vanuxemi. 

Orthis  linneyi.    w.  SP. 

Plate  XXXIV.,  figures  7  to  13. 

Shell  of  medium  size;  sub-circular  or  sub-elliptical;  width  exceeding 
length;  hinge-line  short,  measuring  little  more  than  one-third  the  width  of 
the  shell ;  cardinal  extremities  broadly  rounded ;  lateral  margins  regularly 
curved  ;  basal  margin  broadly  curved,  showing  in  the  dorsal  view  a  slight 
emargination,  and  in  ventral  view  a  small  basal  extension  in  the  central  part 
of  the  front.  (Figure  9,  on  plate  XXXIV.,  shows  a  basal  extension,  where  it 
should  show  a  small  sinus  or  inflection.)  In  regard  to  depth,  it  varies  from 
moderately  convex  to  gibbous. 

Ventral  valve  is  mostly  less  convex  than  the  opposite  one ;  its  greatest  con- 
vexity is  at  the  umbo,  from  where  it  slopes  in  a  more  or  less  curved  line  to 
baso-lateral  margins,  and  more  abruptly  to  the  cardinal  borders ;  central  part 
of  valve  is  depressed,  forming  a  mesial  sinus,  which  extends  from  beak  to 

GEOL.   SUR. — 6 


42  PALAEONTOLOGY    OF    KENTUCKY. 

base,  and  increases  rapidly  in  depth  and  width  towards  front ;  it  has  a  lingui 
form  basal  extension,  which,  however,  does  not  deflect  from  the  regular  curve 
of  the  sinus,  to  meet  the  dorsal  indentation.  Ventral  umbo  is  more  or  less 
prominent  in  different  specimens,  the  beak  elevated,  pointed  and  arched,  but 
not  incurved  ;  hinge-area  is  short  but  high,  forming  in  some  individuals  almost 
an  equilateral  triangle ;  the  larger  portion  of  the  hinge-area  is  occupied  by  a 
comparatively  large,  open,  triangular  fissure.  The  dorsal  valve  is  varying 
from  moderately  convex  to  gibbous,  having  its  greatest  convexity  just  below 
the  umbo,  from  where  it  slopes  in  a  more  or  less  stronger,  regular  curve  to 
the  baso-lateral  margins,  and  abruptly  to  the  apex  and  the  cardinal  borders ; 
it  has  a  mesial  fold  of  moderate  elevation,  which  commences  to  rise  above  the 
general  surface  just  below  the  umbo,  from  where  it  extends  to  the  base,  only 
slightly  increasing  in  width  and  depth.  The  dorsal  umbo  is  somewhat  in- 
flated, and  the  beak  small  and  incurved.  The  dorsal  hinge-area  is  small, 
about  one-half  the  size  of  the  ventral.  The  surface  is  covered  by  simple, 
rounded  or  sub-angular  radiating  plications,  of  which  usually  three,  but 
sometimes  four,  occupy  the  sinus,  and  generally  four,  but  sometimes  five,  are 
placed  on  the  mesial  fold,  while  from  four  to  seven  or  eight  are  seen  on  each 
side  of  the  mesial  fold  or  sinus.  In  some  specimens  of  this  species  there 
exists  a  decided  inequality  in  the  lateral  parts,  consisting  not  so  much  in  size 
as  in  the  number  of  plications.  I  have,  for  instance,  one  shell  before  me, 
where  the  right  side  of  the  dorsal  valve  has  only  four  ribs,  while  the  left  side 
contains  six.  On  the  ventral  valve  is  the  same  difference  between  the  number 
of  the  ribs  of  both  sides.  This  inequality  exists  in  a  good  many,  though  not 
in  all  specimens.  There  is  an  indication  of  very  fine  radiating  lines  on  and 
between  the  plications.  Fine  concentric  lines  cross  the  plications,  which 
become  lamellose  and  imbricating  towards  the  front. 

Formation  and  Locality. — This  species  is  named  in  honor  of  W.  M.  Linney,  the  able  Assistant 
Geologist  of  our  State,  who  collected  this  shell  in  the  shales  of  the  Hudson  River  or  Cincinnati  group, 
near  Danville,  Kentucky.  It  is  found  in  excellent,  almost  perfect  specimens,  and  seems  to  be  somewhat 
abundant  It  also  occurs  in  the  base  of  the  Lower  Hudson,  in  Fayette  and  Franklin  counties,  Kentucky. 

Orthis  nisis.    HALL. 

Plata  XXVII.,  figures  4  and  5, 

Orthis  nisis,  Hall.    24th  Rep.  on  N.  Y.  State  Museum,  page  181 — 1872. 
Orthis  nisis,  Hall.    27th  Rep.  on  N.  Y.  State  Museum,  pi.  9.,  figs.  1-8 — 1875. 

Shell  depressed-pyramidal  when  resting  on  the  dorsal  valve.  Dorsal  valve 
semi-elliptical,  flat  or  slightly  concave  in  middle,  and  gently  convex  on  each 
side.  Length  and  width  about  as  two  to  three ;  area  about  one-quarter  as 
wide  as  that  of  the  ventral  valve.  Ventral  valve  depressed-pyramidal;  the 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  43 

apex  projecting  backwards  over  the  area.  The  elevation  about  equal  to  half 
the  length  of  the  dorsal  valve ;  area  twice  as  wide  as  high,  fissure  very  nar- 
row and  slender,  and  reaching  to  the  apex.  Surface  marked  by  strong  angular 
striae,  which  are  increased  by  interstitial  additions,  to  the  number  of  twenty- 
eight  or  thirty,  on  the  margin  of  the  shell ;  striae  crossed  by  distinct  lines  of 
growth. 

Length,  five  lines  on  the  dorsal  valve ;  width,  seven  lines.  This  species  is 
of  the  type  of  Orthis  tricenaria,  of  the  Trenton  group,  but  its  beak  is  much 
more  elevated,  its  area  higher,  and  its  striae  more  angular,  and  these  are 
increased  by  interstitial  additions,  while  in  O.  tricenaria  and  its'  congener  O. 
pectinella  the  striae  are  simple. 

Formation  and  Locality. — Found  in  the  upper  strata  of  the  Niagara  formation  in  the  quarries  east 
of  the  city  of  Louisville,  Ky.,  where  well  preserved  specimens  are,  however,  rather  rare. 

Orthis  propinqua.    HALL. 

Plate  XVI.,  figures  1,  to  3,  and  7  to  11. 

Orthis  propinqua,  Hall.     Tenth  Rep.  on  St.  Cab.,  p.  110—1857 
Orthis  propinqua,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  43—1857 

Shell  of  more  than  medium  size ;  transversely  elliptical  or  sub-quadrate ; 
varying  from  moderately  convex  to  gibbous ;  hinge-line  about  one-half  the 
width  of  shell ;  cardinal  extremities  broadly  rounded ;  lateral  margins  regu- 
larly curved  beyond  the  front  angles ;  basal  margin  broadly  curved  and  trun- 
cated or  even  somewhat  inflected  in  its  central  part. 

Ventral  valve  less  gibbous  than  the  dorsal ;  very  prominent  at  the  umbo, 
sloping  very  abruptly  towards  the  cardinal  angles,  but  more  gently  towards 
lateral  and  baso-lateral  margins ;  flattened  in  center ;  the  lower  half  marked 
by  a  gradually  increasing,  broad  and  undefined  sinus,  which  gives  a  strongly 
upward  curved  outline  to  basal  or  front  margin ;  beak  acutely  pointed  and 
slightly  incurved ;  cardinal  area  elevated  and  concave,  and  divided  by  a  tri- 
angular foramen,  which  is  open,  and  twice  as  high  as  wide  in  its  base.  The 
dorsal  valve  is  larger  and  more  gibbous  than  the  opposite  one ;  its  greatest 
convexity  fs  a  little  above  the  middle  of  the  length,  curving  abruptly  to  the 
cardinal  and  cardino-lateral  margins,  and  somewhat  more  gently  to  the  front 
and  baso-lateral  margins.  The  cardinal  extremities  are  sometimes  slightly 
deflected,  and  the  surface  at  the  cardinal  angles  a  little  concave.  Cardinal 
area  is  inclined  to  that  of  the  ventral  valve,  and  about  one-half  or  two-thirds 
as  wide.  Surface  marked  by  fine,  unequal,  radiating  striae,  which  increase  in 
number  by  intercalation,  and  are  crossed  by  fine  concentric  striae,  and,  at  un- 
equal intervals,  by  stronger  imbricating,  lamellose  lines  of  growth. 

This  species  resembles  closely  O.   multistriata  of   the    Lower   Helderberg 


44  PALAEONTOLOGY    OF    KENTUCKY. 

group,  from  which  it  differs  only  in  internal  characters.  It  is  also  closely 
allied  to  O.  tulliensis,  from  which  it  can  only  be  distinguished  by  characters  of 
the  interior. 

Formation  and  Locality. — Occurs  in  the  upper  strata  of  the  Devonian  formation,  in  Jefferson 
county,  Kentucky,  and  in  Clark  county,  Indiana.  Fair  specimens  are  rather  rare. 

Orthis  rugaeplicata.    HALL. 

Plate  XXVII.,  figures  1,  2  and  3. 

Orthis  rugaeplicatas,  Hall.    24th  Rep.  N.  Y.  St.  Mus.,  p.  182—1872. 
Orthis  rugaeplicatas,  Hall.    27th  Rep.  N.  Y.  St.  Mus.,  pi.  9,  figs.  1,  2  and  3—1875 

Shell  small,  subquadrate,  four-fifths  as  long  as  wide,  gibbous ;  cardinal  line 
nearly  equal  to  the  greatest  width  of  the  shell ;  cardinal  angles  obtuse,  basal 
margin  nearly  straight.  Dorsal  valve  convex,  with  a  distinct  median  sinus 
extending  from  beak  to  base ;  cardinal  area  linear ;  length  three  lines,  width 
four  lines.  Ventral  valve  depressed-pyramidal,  marked  along  the  center  by  a 
distinct  angular  plication  or  fold ;  beak  projecting  slightly  backwards  over 
the  area ;  area  moderate,  less  than  one- third  as  high  as  wide,  and  divided  in 
the  center  by  a  moderately  wide  fissure. 

Surface  marked  by  very  strong,  sharply  angular  plications,  which  are  in- 
creased by  interstitial  additions,  and  of  which  there  are  about  fifteen  on  the 
margin  of  each  valve,  with  a  few  other  incipient  ones. 

Formation  and  Locality. — Found  in  the  Niagara  formation  in  the  quarries  east  of  the  city  of 
Louisville,  Ky.  It  is,  when  well  preserved,  an  elegant  little  shell:  but  perfect,  even  fair  specimens,  are 
very  rare ;  those  of  Dr.  James  Knapp,  deceased,  and  my  own,  are  all,  so  far  found 

Orthis  subnodosa.    HALL. 

Orthis  subnodosa,  Hall.    Trans.  Alb.  Inst.,  Yol.  X.— 1879. 
Orthis  subnodosa,  Hall,     llth  Geol.  Rep.  of  Ind.,  p.  286—1881. 

It  appears  from  Prof.  Hall's  description  and  illustration  in  the  above  men- 
tioned report  of  Indiana,  that  he  was  then  in  possession  of  only  the  ventral 
valve  of  this  species,  and  the  same  is  the  case  with  me  to-day.-  Prof.  Hall 
describes  this  shell  as  follows : 

Ventral  valve  sub-orbicular,  length  and  width  about  as  ten  to  fourteen ; 
hinge-line  much  shorter  than  the  greatest  width  of  the  shell ;  an  undefined 
mesial  depression  in  the  lower  half  of  the  shell.  (In  this  last  feature  my 
shell  differs  from  Prof.  Hall's,  in  having  this  depression  extend  all  the  way 
up  to  the  apex,  but  it  is  possible  that  this  extended  sinus  was  caused  by 
the  breaking  off  of  one  of  the  adjacent  ribs.)  The  umbo  is  comparatively 
prominent ;  beak  small  and  slightly  arched  ;  area  small,  triangular,  apparently 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  45 

hot  occupying  more  than  half  the  width  of  the  valve ;  foramen  large,  triangu- 
lar, reaching  to  the  beak,  wider  than  high.  Surface  marked  by  sub-angular 
plications,  of  which  three  occupy  the  mesial  sinus,  the  central  one  being  inter- 
stitial, coming  in  below  the  umbo ;  there  are  about  ten  plications  on  each  side 
of  the  mesial  depression ;  some  of  them  originate  by  bifurcation  or  intercala- 
tion. The  radii  are  crossed  by  fine  concentric  lamellose  lines  of  growth, 
which  gives  them  a  sub-nodose  appearance.  This  species  has  some  resem- 
blance to  Orthis  fissicosta,  of  the  Hudson  River  group,  but  its  cardinal  ex- 
tremities are  more  rounded  and  its  cardinal  area  is  not  as  high. 

Formation  and  Locality. — Prof.  Hall's  specimen  was  found  at  Waldrori,  Indiana,  and  that  before 
me  I  collected  in  the  quarries  east  of  the  city  of  Louisville.  It  was  imbedded  in  the  white  Niagara  clay. 

Orthis  vanuxemi.    HALL. 

Plate  XVI.,  figures  4,  5,  6,  12,  12o,  13  and  14. 
Orthis  vanuxemi.  Hall.     Tenth  Hep.  on  St.  Cab.,  p.  136 — 1857. 
Orthis  vanuxemi.  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  47—1867. 

Shell  above  medium  size,  sub-circular,  or  transversely  sub-elliptical ;  upper 
part  of  the  shell  bi-convex ;  lower  or  front  part  generally  concavo-convex ; 
shell  strongly  compressed ;  hinge-line  very  short,  little  more  than  one-third 
the  width  of  the  shell ;  cardinal  angles  broadly  rounded ;  lateral  margins 
strongly  curved,  and  the  front  in  its  central  half  inflected  or  emarginate. 
Ventral  valve  mostly  concave  or  sometimes  flat,  with  the  exception  of  the 
umbonal  region,  which  is  slightly  convex ;  beak  small,  seldom  extending 
beyond  that  of  the  dorsal  valve,  but  often  even  somewhat  less  elevated ;  it 
is  pointed  and  gently  arched,  but  not  incurved ;  cardinal  area  small,  forming 
a  low  triangle,  which  is  divided  in  its  center  by  a  small  triangular  foramen, 
partly  filled  by  the  cardinal  process  of  the  opposite  valve.  Dorsal  valve 
moderately,  but  even  and  regularly  convex  over  the  whole  surface  of  the 
valve,  with  the  exception  of  the  umbonal  region,  which  is  slightly  more  con- 
vex ;  the  beak  is  scarcely  distinct  from  the  cardinal  border  and  not  incurved  ; 
cardinal  process  prominent  and  partly  closing  the  ventral  foramen ;  cardinal 
area  small,  about  two-thirds  as  wide  as  the  ventral,  flat  and  inclined  towards 
that  of  the  opposite  valve. 

Surface  of  both  valves  ornamented  by  fine,  closely  arranged,  radiating 
tubular  striae,  which  are  perforate  at  intervals,  increasing  in  number  partly 
by  bifurcation  and  partly  by  intercalation,  and  crossed  by  very  fine  indistinct 
concentric  lines,  and  at  greater  intervals,  by  more  distinct  concentric,  imbri- 
cating lines  of  growth  ;  entire  surface  granulate  or  punctate  under  a  magnifier. 
Striae  from  twelve  to  sixteen  in  the  space  of  two  lines  near  the  beak,  and 
from  seven  to  nine  in  same  space  near  margin. 


46  PALEONTOLOGY    OF    KENTUCKY. 

This  species  resembles  closely  Orthis  michelini,  of  Laveille,  but  shows  several 
points  of  difference.  The  later  species  is  here,  in  our  Carboniferous  rocks, 
greatly  more  compressed. 

Formation  and  Locality. — The  specimens  figured  show  the  general  size.  Occurs  in  the  upper 
strata  of  the  Devonian  formation  in  Jefferson  county,  Ky.,  and  in  Clark  county,  Indiana. 

Genus  Tropidoleptus.    Han. 

Tropidoleptus,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  404—1867. 
Etymology:  tropis,  a  carina;  and  leptos,  slender. 

Shell  transversely  sub-oval  or  semi-elliptical,  concavo-convex;  hinge-line 
extended,  not  crenulate ;  articulating  by  teeth  and  sockets.  Ventral  valve 
convex,  with  a  distinct  area  and  wide  fissure  beneath  the  beak.  Dental 
lamellae  distinct  from  the  margin  of  the  fissure ;  crenulate. 

Dorsal  valve  concave,  with  crenulate  dental  fossets ;  a  strong  cardinal  pro- 
cess with  diverging  lobes  in  interior,  which  support  slender  crura  that  converge 
to  and  unite  with  the  median  crest.  Surface  plicate ;  shell  structure  punctate. 

Type  of  the  genus  is  T.  carinatus. 

Tropidoleptus  carinatus.    CONRAD. 

Plate  XVII.,  figures  14  and  15. 

Strophomena  carinata,  Conrad.     Ann.  Geol.  Rep.,  p.  64 — 1839. 
Leptaena  laticosta,  Hall,  in  1883. 
Leptaena  laticosta,  of  Owen  and  others. 

Tropidoleptus  carinatus,  Hall.     Tenth  Rep.  on  St.  Cab.,  p.  151 — 1857. 
Tropidoleptus:  Genus  described  and  illust.  in  12th  Rept. on  St.  Cabinet. — 1869. 
Tropidoleptus  carinatus,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  407—1867. 

Shell  of  medium  size,  concavo-convex,  semi-elliptical,  length  sometimes 
nearly  equalling  width  ;  hinge-line  variable  in  size,  but  generally  a  little  less 
than  greatest  width  of  shell ;  cardinal  extremities  rarely  rounded,  generally 
forming  with  the  lateral  margins  an  obtuse  or  right-angle.  The  lateral  mar- 
gins are  of  double  curvature,  starting  from  the  cardinal  extremities,  they  curve 
at  first  inward  for  about  one- fourth  of  the  length,  thence  they  curve  outwards, 
combining  with  broad  curve  of  base  to  an  almost  regular  semi-circle. 

Ventral  valve  ventricose,  sub-carinate  in  the  center  by  a  stronger  and  more 
elevated  plication,  forming  a  kind  of  mesial  fold,  from  which  the  valve  slopes 
in  a  gentle  curve  to  lateral  and  basal  margins  ;  umbo  small,  and  the  beak 
somewhat  encroached  upon  by  the  broad  foramen ;  cardinal  area  narrow,  ex- 
tending to  the  extremities,  its  margins  almost  parallel  with  t}ie  hinge-line  ; 
the  cardinal  angles  deflected.  The  area  is  longitudinally  striate,  which  feature 
is,  however,  obliterated  in  silicified  specimens. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  47 

Dorsal  valve  moderately  concave,  sometimes  nearly  flat,  often  with  a  slight 
mesial  depression  or  sinus,  which  is  usually  only  noticeable  in  the  basal  half ; 
apex  small  and  projecting  a  little  beyond  the  hinge-line,  partly  closing  the 
triangular  fissure  of  the  other  valve.  There  is  a  narrow,  almost  linear  area, 
interrupted  in  the  middle  by  a  wide  pseudo-deltidium  which  covers  the  ex- 
tremity of  the  cardinal  process.  Surface  marked  by  about  eighteen  to  twenty 
broad,  simple,  rounded  plications,  which  are  wider  than  the  spaces  between 
them.  The  central  one  on  the  ventral  valve  is  stronger  and  more  elevated  than 
the  balance,  while  on  the  dorsal  valve  there  is  a  corresponding  wider  and 
deeper  groove.  Bifurcation  is  only  noticed  in  rare  instances.  Fine  undulating, 
concentric  striae  ornament  the  surface,  and  some  stronger  imbricating  lamellae 
mark  the  different  stages  of  growth.  It  appears  that  our  Kentucky  specimens 
differ  slightly  from  the  New  York  ones,  which  latter  have  rounded  extremities 
and  almost  straight  lateral  margins,  while  in  the  Kentucky  specimens  extremi- 
ties and  lateral  margins  are  as  before  mentioned. 

Formation  and  Locality. — In  the  upper  strata  of  the  Devonian  limestone  in  Clark  county,  In- 
diana, and  some  few  places  south-east  of  the  city  of  Louisville,  Ky.  The  Indiana  specimens  are  very 
tine  and  perfect,  often  showing  the  two  valves  separated,  except  -at  the  hinge.  Our  shells  are  almost  all 
silicified  and  have  different  sizes ;  the  one  represented  on  plate  XVII.  belongs  to  the  larger  ones. 

Genus  Anastrophia.    Han. 

Anastrophia,  Hall.     Pal.  N.  Y.,  Yol  IV.,  p.  373—1867. 

Etymology:  ana,  witfi;  strophe,    a  turning  round,   alluding    to  the  valves  having   reverse    relation;    the 
dorsal  valve  is  larger  than  the  other,  and  its  beak  overlaps  the  ventral  beak. 

Shell  rotund  or  gibbous,  with  the  valves,  as  in  ordinary  Pentamerus,  reversed. 
The  ventral  valve  is  the  smaller,  gibbous  in  its  upper  part,  depressed  or  sinuate 
below,  with  the  Y-shaped  pit  sessile  for  nearly  its  entire  length  ;  a  small  flat- 
tened space  on  each  side  of  the  fissure.  The  dorsal  valve  is  ventricose,  larger 
than  the  ventral,  with  prominent  umbo.  The  hinge-plate  is  extended  in  gradu- 
ally converging  vertical  lamellae,  which  are  joined  to  the  shell  throughout  their 
length,  while  the  crura  are  extended  into  the  cavity  in  thin  free  lamellae.  The 
species :  Pent,  verneuilli,  P.  internascens  and  P.  reversus  are  the  types  of  this 

new  genus. 

Anastrophia  internascens.    HALL. 

Plate  XXXII.,  figures  17  to  20. 

Anastrophia  internascens,  Hall,     llth  Geol.  Kep.  of  Indiana — 1881. 
See  list  of  synonyms  in  said  llth  Rep.  of  Indiana. 

Shell  transversely  sub-elliptical,  ovoid  or  sub-globose  in  different  stages  of 
growth ;  the  length  and  width  are  sometimes  nearly  equal.  Valves  of  young 
specimens  nearly  equal  in  convexity,  in  older  individuals  the  dorsal  valve 


48  PALAEONTOLOGY    OF    KENTUCKY. 

becomes  the  more  gibbous.  Ventral  valve  moderately  convex  in  young  or 
medium  sized  specimens,  and  gibbous  in  the  upper  part  of  old  ones ;  the 
anterior  portion  depressed,  and  marked  by  a  broad,  undefined  sinus  ;  beak 
short,  acute,  closely  incurved  over  the  umbo  of  the  opposite  valve,  area  small, 
short  and  sharply  denned.  Dorsal  valve  gibbous,  and  in  old  individuals  the 
umbo  projects  beyond  the  beak  of  the  ventral  valve,  with  the  apex  incurved 
beneath  the  beak  of  the  latter ;  central  portion  of  the  valve  toward  the  front 
more  elevated,  and  sometimes  presenting  a  broad,  undefined  mesial  fold.  Sur- 
face plications  abruptly  elevated,  rounded,  angular  or  sub-angular,  becoming 
depressed  and  sometimes  obsolete  on  the  cardinal  slopes,  usually  simple,  en- 
larging toward  the  front  of  the  shell,  rarely  bifurcating  or  intercalating  in  a 
remarkable  manner  on  the  sides,  where  the  folds  bend  abruptly  outwards  to 
the  cardino-lateral  margins  ;  plications  crossed  by  arching  imbricating  striae 
or  lines  of  growth,  which  are  sometimes  very  conspicuous.  The  dimensions 
of  this  species  are  very  variable  in  different  individuals.  The  figures  on  plate 
XXXII.  show  the  average  size  of  Louisville  specimens. 

Formation  and.  Locality. — Occurs  in  the  Niagara  strata  in  the  quarries  east  of  the  city  of  Louis- 
ville, Ky.,  in  fine,  well  preserved  specimens,  which  are,  however,  rather  rare,  and  which  never  attain  the 
size  of  individuals  from  "Waldron.  To  avoid  mistakes,  I  will  here  draw  the  attention  of  the  students  of 
palaeontology  to  the  fact  that  in  this  species  the  valves  are  easily  confounded,  inasmuch  as  the  dorsal  one 
is  larger  than  the  other,  and  its  beak  generally  more  prominent  than  the  one  of  the  ventral  valve. 

Genus  Camarella.    Bnimgi. 

Camerella,  Billings.     Can.  Nat.  and  Geol.,  Vol.  4 — 185.9. 
Etymology:  Kamara,  arching  chamber;  ella,  diminutive. 

This  genus  was  established  by  Mr.  Billings  in  1859,  but  I  have  never  been 
able  to  see  the  description  of  his  genus,  which  he  should  have  repeated  in  his 
"Palaeozoic  Fossils"  of  the  Geology  of  Canada,  Volume  I.,  1861  to  1865,  where 
he  describes  eight  different  species  of  this  genus. 

i  The  different  shells  which  he  places  in  his  new  genus  have  the  following 
characteristics :  Shells  sub-circular  or  ovate,  unequivalve  but  equilateral ; 
both  valves  more  or  less  convex,  having  their  greatest  width  below  the  middle 
of  the  length,  usually  close  to  the  base  or  front.  The  surface  is  generally 
plicated  but  also  smooth,  and  only  marked  by  concentric  lines  of  growth.  The 
internal  characters  of  this  genus  are  not  known. 

Camerella  congesta.     CONRAD. 

Atrypa  congesta,  Conrad.     Jour.  Acad.  Nat.  Sci.  Phil.,  Vol.  8 — 1842. 
Atrypa  congesta,  Hall.     Geol.  Rep.  4th  Dist.  N.  Y.,  p.  71—1343. 
Atrypa  congesta,  Hall.     Pal.  N.  Y.,  Vol.  II.,  p.  67—1852. 

Shell  sub-orbicular,  gibbous,  often  more  or  less  ovate,     Ventral  valve  much 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  49 

larger  and  more  elevated  at  the  beak  than  the  dorsal  valve,  with  a  deep  mesial 
furrow,  which  commences  at  the  beak  and  gradually  deepens  and  widens 
towards  the  base  or  front  of  the  valve,  where  it  forms  a  linguiform  basal  ex- 
tension, which  is  strongly  elevated  to  fit  into  a  corresponding  indentation  of 
the  dorsal  valve.  The  mesial  depression  of  the  ventral  valve  is  margined  by 
a  more  or  less  obtusely  carinated  fold,  produced  by  a  depression  of  the  shell  on 
each  side  of  the  sinus.  Dorsal  valve  with  a  strong,  elevated  mesial  fold,  and 
a  depression  on  each  side,  beyond  which  is  sometimes  an  obscure  fold.  Beak 
of  the  ventral  valve  elevated  and  strongly  incurved  over  beak  of  opposite 
valve,  while  the  dorsal  beak  is  small  and  incurved.  The  entire  surface  is 
covered,  in  well  preserved  specimens,  with  fine  concentric  striae,  and  with  a 
few  imbricating  lines  of  growth  near  the  front.  The  specimen  before  me  does 
not  show  any  of  these  lines  on  account  of  its  silicified  condition.  This  species 
is  subject  to  considerable  variations  in  its  form,  but  is,  in  spite  of  that,  easily 
identified  by  its  rotund  and  gibbous  form. 

Formation  and  Locality. — This  species  usually  occurs  in  the  lower  strata  of  the  Clinton  group; 
but  I  found  my  specimen  in  the  Niagara  rocks  near  our  city,  from  which  it  appears  that  the  lower  strata 
of  our  Upper  Silurian  rocks  must  belong  to  that  group,  as  is  also  indicated  by  several  other  fossils  of  de- 
cidedly Clinton  character. 

Genus  Pentamerella.    Han. 

Pentamerella,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  373—1867. 
Etymology :  Diminutive  of  pentamerus. 

Shells  ovate,  more  or  less  rotund,  with  a  sinus  on  the  ventral  valve,  and  a 
mesial  fold  on  the  dorsal  valve ;  internal  structure  of  the  ventral  valve  as  in 
Pentamerus  knighti.  Dorsal  valve  with  the  crura  or  lamellae  of  the  hinge- 
plate  conjoined,  so  as  to  form  a  separate,  trough-shaped  cavity,  which  unites 
with  the  inner  surface  of  the  valve  ;  a  narrow  area  on  each  side  of  the  fissure, 
and  a  flattened  space  or  a  false  area  along  the  cardinal  margin  of  the  valve. 
Pentamerella  arata  is  the  type  of  this  genus. 

Pentamerella  arata.    CONRAD. 

Plate  XIII.,  figures  17  to  20. 

Atrypa  arata,  Conrad.     Ann.  Rep.  on  Pal.  of  N.  Y.,  p.  55 — 1851. 
Atrypa  octocostata,  Id.  Ib. 

Pentamerus  aratus,  Hall.     Tenth  Eep.  St.  Cab.,  p.  120—1857. 
Pentamerella  arata,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  375—1867. 

Shell  of  medium  size,  ovate,  more  or  less  convex  or  gibbous,  becoming 
arcuate-ovoid  in  old  shells ;  proportion  of  length  to  width  variable ;  in  most 
cases  both  are  equal,  but  in  some  individuals  the  width  exceeds  the  length, 

QEOL.    SUR. — 7 


50  PALAEONTOLOGY    OF    KENTUCKY. 

and  in  others  the  length  is  the  larger.  Hinge-line  is  also  very  variable ;  in 
some  specimens  it  is  scarcely  noticeable,  in  others  of  considerable  size.  Ven- 
tral valve  regularly  convex  in  young  individuals,  but  becoming  gibbous  in  old 
ones.  The  mesial  sinus  is  regularly  developed,  but  undefined  and  very  shal- 
low, even  at  the  front ;  it  starts  below  the  umbo  and  forms  a  slight  convexity 
in  the  basal  margin,  which  is  in  most  shells  regularly  curved ;  beak  elevated 
and  strongly  incurved  over  the  fissure,  which  it  partly,  sometimes  wholly, 
closed ;  the  foramen  almost  as  wide  in  the  base  as  its  height ;  cardinal  area 
sometimes  scarcely  visible,  while  again  in  some  shells  it  forms  a  regular  tri- 
angle; bounded  by  a  faint  but  distinct  elevation  on  each  margin.  Dorsal  valve 
in  young  shells  more  or  less  convex,  and  sometimes  gibbous  in  the  upper  part, 
and  often  only  moderately  convex  in  older  shells ;  mesial  fold  starts  below 
the  umbo,  never  well-defined,  and  not  much  elevated,  still  distinctly  developed. 
Surface  ornamented  by  rounded  or  sometimes-  by  somewhat  angular  plications, 
which,  in  rare  instances,  reach  all  the  way  back  to  the  apex,  but  which  are 
generally  limited  to  the  lower  half  or  two-thirds  of  the  valve ;  they  increase 
by  bifurcation.  The  interior  of  the  ventral  valve  has  an  elongate  spoon- shaped 
pit ;  the  inner  extremity  of  which  is  free  for  a  considerable  extent,  and  the 
upper  part  supported  on  a  central  septum,  which  usually  extends  less  than 
half  the  length  of  the  shell  from  the  apex.  In  the  dorsal  valve,  the  crura  or 
lamellae  are  conjoined  at  their  bases,  making  a  Y-shaped  trough  or  pit,  which 
is  attached  to  the  valve  in  its  upper  part  and  continues  sessile  for  about  one- 
half  the  length  of  the  shell.  This  species  shows  much  variety  in  aspect  and 
form,  caused  by  age  and  the  conditions  under  which  it  lived,  which  were  either 
favorable  or  unfavorable  to  its  development.  Conrad's  species,  Atrypa  octo- 
costata,  includes  forms  which  are  easily  connected  by  intermediates  with  Pent, 
arata,  and  which,  therefore,  belong  to  this  species.  In  size  it  differs  greatly. 
The  figures  on  plate  XIII.  represent  an  individual  of  more  than  average 
size. 

Formation  and  Locality. — Occurs,  not  rarely,  in  the  Corniferous  limestone  of  Kentucky  and  Indi- 
ana, at  and  around  the  Falls  of  the  Ohio,  where  fair  and  sometimes  even  very  fine  specimens  are  procured. 

Fentamerella  papilionensis.    HALL. 

Pentamerus  papilionensis,  Hall.     Geol.  Hep.  of  Iowa,  Vol.  I.,  part  II.,  cited  on  page  514 — 1860. 
Pentamerus  papilionensis,  Hall.     Thirteenth  Rep.  on  the  State  Cabinet,  p.  86 — 1860. 
Pentamerella  papilionensis,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  377 — 1867. 

Shell  of  medium  size,  ventricose,  broadly  ovate,  often  wider  than  long,  more 
or  less  gibbous  and  arcuate  in  old  shells. 

Ventral  valve  gibbous  or  ventricose  above,  becoming  depressed  in  the  middle 
into  a  broad,  shallow,  undefined  sinus,  which  scarcely  reaches  to  the  beak,  and 


FOSSILS    Otf    THE    SILURIAN    AND    DEVONIAN    BOOKS.  5i 

in  some  cases  not  much  above  the  middle,  and  is  little  produced  in  front.  1 
have  a  specimen  before  me,  where  the  plication  of  the  mesial  sinus  is  even 
overreaching  the  general  surface  of  the  valve ;  sides  curving  abruptly  to  the 
margins ;  beak  incurved,  obtuse,  arching  over  the  broad  fissure  ;  cardinal  area 
sloping  on  both  sides  down  to  about  the  middle  of  the  valve,  bounded  by  a 
sharp,  somewhat  curved  line  of  demarcation,  having  a  considerable  size  and 
being  somewhat  concave. 

Dorsal  valve  moderately  convex  and  regularly  curving  to  the  lateral  and 
basal  margins  ;  mesial  fold  not  much  elevated,  and  limited  to  the  lower  half 
of  the  valve,  where  it  is  well  defined.  Surface  plicated,  the  ribs  rounded  or 
sub-angular,  becoming  obsolete  towards  the  beak,  and  prominent  in  the  basal 
half.  There  are  generally  two,  sometimes  three  plications  in  the  sinus,  and 
three,  rarely  four  on  the  fold,  while  the  lateral  slopes  of  the  valves  contain 
from  four  to  five.  The  plications  are  crossed  by  fine  concentric  lines  of  growth, 
which  sometimes  at  irregular  intervals  are  crowded  into  squamose,  imbricating 
lines.  The  entire  surface  is  finely  papillose  or  punctate,  and,  when  well  pre- 
served, might  be  mistaken  for  a  punctate  shell.  The  substance  of  the  shell 
is  lamellose -prismatic  and  brittle.  The  interior  of  the  ventral  valve  shows  a 
broad,  short  and  deep  spoon-shaped  pit,  extremity  of  which  is  bent  abruptly  to 
dorsal  side.  The  septum,  supporting  the  conjoined  lamellae,  extends  from 
one-third  to  one-half  the  length  of  the  valve,  and  in  some  examples  may 
extend  still  further"  towards  the  anterior  margin.  This  species  bears  much 
resemblance  to  P.  arata,  but  its  plications  are  less  numerous  on  the  whole 
valve ;  less  numerous  and  stronger  in  the  mesial  depression  and  elevation, 
and  its  shell  is  less  arcuate. 

Formation  and.  Locality. — Found  in  the  Corniferous  limestone  in  the  neighborhood  of  the  Falls  of 
the  Ohio  in  Kentucky  and  Indiana.  Pretty  abundant,  but  fair  specimens  rather  rare. 

Fentamerella  thusnelda.    N.SP. 

Plate  XXXI.,  figures  26,  27  and  28. 

Shell  of  medium  size,  ovoid  or  sub-quadrate;  cardinal  extremities  rounded, 
forming  in  the  beak  of  the  dorsal  valve  an  angle  of  a  little  more  than  sixty 
degrees ;  length  exceeding  the  width  considerably,  giving  to  the  shell  an  elon- 
gate, somewhat  slender  appearance.  Ventral  valve  ventricose,  even  gibbous ; 
convexity  regular  from  beak  to  front,  and  also  transversely ;  greatest  convexity 
a  little  above  the  middle  of  the  valve ;  mesial  sinus  indicated  by  two  very 
strong  plications,  and  by  a  wide  and  deep  groove  on  each  side  of  them ;  the 
summit  of  these  plications  drops  not  at  all,  or  at  least  very  slightly,  at  the  very 
front  of  the  valve,  below  the  regular  surface ;  the  two  prominent  grooves  ex- 
tend almost  to  the  beak,  forming  on  the  umbo  only  one  rib,  which  separates 


&2  PALEONTOLOGY    OF    KENTUCKY. 

into  two  plications  in  front  of  the  beak ;  these  mesial  ribs  are  considerably 
prolonged  in  front,  producing  a  sub-quadrilateral  extension  ;  beak  is  prominent 
and  incurved ;  cardinal  area  large,  extending  to  the  extremities,  and  bounded 
by  a  well-marked,  regularly  curved  line  of  demarcation  ;  fissure  of  moderate 
size,  but  partly  closed  by  the  beaks  of  both  valves. 

Dorsal  valve  depressed  convex,  curved  slightly  in  the  upper  half  of  the 
valve ;  lateral  portions  of  lower  half  almost  flat ;  mesial  fold  formed  by  three 
strong  plications,  which  are  united  into  one  single  elevation  on  the  umbo, 
where  it  is  only  faintly  visible ;  below  the  umbo  the  three  mesial  ribs  separate 
and  extend  to  a  little  beyond  the  front,  where  they  are  considerably  elevated  ; 
beak  moderate  and  incurved  into  the  foramen  of  the  other  valve  ;  cardinal 
area  only  linear.  Surface  marked  by  about  twelve  sub-angular  plications,  of 
which  those  in  the  mesial  depression  and  elevation  are  considerably  stronger 
than  those  on  the  lateral  slopes  ;  the  lateral  ribs  on  the  dorsal  valve  are  single 
and  of  equal  size;  those  on  the  ventral  valve  increase  by  bifurcation,  and  those 
nearest  to  the  mesial  furrows  appear  to  be  stronger  than  the  more  lateral 
ones. 

This  species  resembles  Pent,  arata  and  Pent,  papilionensis,  also  Pent,  dubia  ; 
from  Pent,  arata  it  differs  by  its  elongate  form,  its  less  numerous  plications, 
and  by  its  mesial  ribs,  which  are  here  limited  to  three  in  the  fold  and  two  in 
the  sinus,  and  which  are  of  about  double  size  of  the  lateral  ones ;  while  in 
Pent,  arata  the  mesial  plications  are  larger  in  number  and  of  almost  equal  size 
with  the  balance.  From  Pent,  papilionensis  it  differs  in  its  elongate  form,  and 
in  the  peculiar  character  of  the  mesial  plications,  which  in  P.  papilionensis 
have  the  same  number,  but  do  not  differ  from  the  lateral  ones  by  size;  and 
from  Pent,  dubia  it  differs  also  in  form  ;  while  P.  dubia  has  its  greatest  width 
about  the  middle  of  the  shell,  this  one  has  its  maximum  breadth  nearer  to  the 
front,  at  more  than  two-thirds  from  the  apex;  P.  dubia  has  more  plications 
generally,  and  also  more  on  the  fold  and  in  the  sinus. 

Formation  and  Locality. — Found  in  the  Corniferous  limestone  surrounding  the  Falls  of  the  Ohio 
in  Kentucky  and  Indiana.  It  is  of  rare  occurrence  here  in  the  neighborhood  of  the  falls ;  only  two  indi- 
viduals of  this  species  are  known ;  they  belong  to  my  own  cabinet. 

Genus  Pentamerus. 

Pentamerua,  Sowerby.     Min.  Couch.,  Vol.  I. — 1814. 
Etymology:  penta,  five;  meros,  apartments. 

This  genus  was  proposed  by  Sowerby  in  1813  to  include  all  the  shells  allied 
to  Pent,  knighti,  which  he  made  the  type  of  the  genus  Pentamerus.  Dalman 
objecting  to  the  name,  on  the  ground  that  the  shell  was  not  five-chambered, 
proposed  in  its  stead  the  name  Gypidia,  but  this  latter  was  never  accepted. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  53 

This  genus  included  for  a  while  a  large  number  of  related  species,  but  there 
existed  differences  which  compelled  the  division  into  several  genera,  which 
Prof.  Hall  and  Mr.  Billings  established.  Prof.  Hall  gives  the  characteristics 
of  Pentamerus  as  follows :  Shells  having  rotund  or  gibbous  forms,  with  the 
ventral  valve  prominent  in  the  middle,  and  the  dorsal  valve  flattened  or  de- 
pressed towards  the  front ;  lamellae  of  the  dorsal  valve  distinct,  as  P.  knighti, 
P.  galeatus  and  P.  pseudogaleatus.  Or  the  form  is  elongate,  with  the  valves 
sub-equally  convex,  lobed  or  sub-sinuate ;  internal  structure  like  that  of  P. 
knighti,  as  P.  oblongus  and  P.  lens,  etc. 

Pentamerus  complanatus.     K.  sr. 

Plate  XXVII.,  figures  14,  15  and  16. 

Pentamerus  nysius,  var.  tenicosta,  Hall.      27th  Rep.  of  N.  Y.  State  Museum,   plate  10,  figures  1,  2  and  3. 

Prof.  Hall  described,  in  the  24th  Report  on  the  N.  Y.  State  Museum,  pages 
184  and  185,  a  new  species,  the  Pentamerus  nysius,  and  distinguished  of  the 
same  the  two  varieties :  Pent,  nysius,  var.  crassicosta  and  Pent,  nysius,  var. 
tenuicosta.  In  the  27th  Report  on  plate  10,  he  figured  two  different  shells,  one 
sub-figures  1,  2  and  3,  and  the  other  sub-figures  4,  5,  6  and  7,  and  placed  both 
in  his  new  species.  The  great  diversity  in  their  form  Prof.  Hall  regards  as 
the  results  of  age,  but  not  of  specific  importance.  Only  on  account  of  the 
different  size  of  their  radii,  he  placed  them  into  different  varieties.  Now  I 
have  before  me  more  than  fifty  specimens,  and  find  among  them  both  forms, 
each  one  represented  by  specimens,  from  very  young  or  small  to  very  old  or 
large,  showing  that  the  age  did  not  cause  the  diversity  of  form,  as  shown  in 
Prof.  Hall's  two  shells.  This  difference  in  shape  I  consider  of  sufficient  impor- 
tance to  base  upon  it  a  new  species,  and  the  only  question  is  now,  which  of  the 
two  forms  shall  retain  the  original  name,  and  which  shall  form  the  new  species. 
The  elongated  and  very  gibbous  shells  represented  by  figures  4,  5,  6  and  7,  show 
a  marked  difference  in  the  size  of  their  costae,  which  necessitates  the  separa- 
tion of  the  species  into  two  varieties,  to  be  designated  as  crassicostus  and 
tenuicostus ;  I,  therefore,  retain  the  original  name  for  this  form,  while  the 
shell,  represented  by  the  figures  1,  2  and  3,  forms  the  new  species  with  the  fol- 
lowing description :  Shell  of  medium  size,  broadly  triangular,  with  little 
gibbosity ;  both  valves  almost  equal  in  size,  form  and  convexity.  The  regular 
curve  of  the  front  margin  is  only  slightly  disturbed  by  a  faint  mesial  exten- 
sion; the  lateral  margins  are  nearly  straight  from  the  apex  down  to  two- 
thirds  of  the  length,  and  slightly  curved  towards  the  front.  None  of  the 
shells  show  the  least  indication  of  a  mesial  depression  or  elevation ;  surface 
marked  by  fine  radii ;  ventral  valve  a  little  more  convex  than  the  other,  being 
depressed  convex ;  greatest  convexity  below  the  umbo,  from  where  it  slopes 


54  PALAEONTOLOGY    OF    KENTUCKY. 

in  a  slightly  curved,  almost  straight  line  to  the  front ;  towards  the  lateral 
margins  it  slopes  in  a  gentle,  regular  curve,  but  approaching  the  margins,  it 
turns  rapidly  towards  the  dorsal  valve,  where  it  forms  a  smooth  border ;  the 
beak  is  small,  straight,  and  very  little  elevated  above  that  of  the  dorsal  valve, 
often  touching  the  same  at  equal  height.  The  dorsal  valve  is  depressed  convex, 
maximum  convexity  below  the  umbo,  from  where  it  slopes  in  a  very  gentle 
but  regular  curve  to  front  and  sides ;  only  a  very  small  strip  of  this  valve  at 
the  lateral  margins  is  rapidly  and  abruptly  bent,  to  meet  the  smooth  marginal 
border  of  the  ventral  valve ;  the  umbonal  part  is  strongly  curved  towards  the 
other  half  of  the  shell ;  the  beak  strongly  incurved  beneath  or  against  the  other 
beak. 

Surface  is  marked  by  fine  radiating  striae,  single  and  rounded,  and  number- 
ing from  thirty  to  forty.  The  surface  is  generally  divided  by  three  promi- 
nent lines  of  growth  into  four  zones,  which  are  easily  noticed  on  any  fair  speci- 
men. The  umbonal  zone  is  always  smooth,  either  the  striae  did  not  develop 
before  a  certain  age,  or  if  this  portion  was  ever  covered  with  radii,  they  became 
obliterated  in  the  course  of  time. 

Formation  and  Locality. — This  beautiful  species,  of  which  my  own  cabinet  possesses  a  few  very  fine 
and  perfect  specimens,  is  found  in  the  Niagara  rocks  in  the  quarries  east  of  Louisville,  Ky.  It  is  very 
rare. 

Pentamerus  globulosus.    K.SP. 

Shell  very  small ;  sub-globose ;  width  exceeding  the  length ;  very  ventricose 
or  gibbous ;  ventral  valve  very  convex ;  greatest  convexity  about  the  middle 
of  the  valve,  from  where  it  slopes,  in  a  regular  but  strong  curve,  to  the  beak 
and  to  the  lateral  and  basal  margins ;  to  the  cardinal  lines  it  slopes  more 
abruptly,  joining  with  the  curved  margins  of  the  hinge-area ;  the  cardinal  area 
is  small  and  not  defined  in  its  margins,  which,  as  before  stated,  are  curved  and 
coalesce  with  the  surface  of  the  valve ;  umbo  is  very  prominent ;  the  beak  is 
elevated  and  strongly  incurved,  but  does  not  touch  the  beak  of  the  opposite 
valve,  from  which  it  remains  sufficiently  distant  to  show  a  moderately  sized, 
open,  triangular  foramen  in  the  ventral  hinge-area. 

Dorsal  valve  is  sometimes  as  convex  as  the  ventral,  though  usually  it  is  less 
so.  It  is  most  convex  in  the  umbonal  region,  but  flattens  in  the  lateral  parts. 
Below  the  middle  of  the  valve  its  central  part  becomes  depressed  into  a  shal- 
low sinus,  which  does  not  reach  beyond  the  basal  third  of  the  valve ;  it  is  most 
perceptible  in  the  basal  margin,  outside  of  which  it  is  scarcely  to  be  noticed. 
Corresponding  with  this  mesial  sinus  the  ventral  valve  shows  a  mesial  elevation, 
which  is  also  confined  to  the  basal  third  of  the  valve,  and  outside  of  the  front 
margin  hardly  observable.  In  some  specimens  these  mesial  depressions  and 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    BOCKS.  55 

elevation  are  not  at  all  indicated.  The  surface  of  the  larger  portion  of  both 
valves  is  entirely  smooth  ;  the  basal  margin  shows,  however,  from  eight  to  ten 
plications  of  different  strength  and  extent  on  each  valve ;  the  central  ones  are 
stronger  and  longer  than  the  balance ;  they  diminish  in  size  and  length  accord- 
ing to  their  distance  from  the  central  point  of  the  base.  None  of  these  plica- 
tions extend  beyond  the  basal  third  ;  most  of  them  are  confined  to  the  border. 
An  average-sized  specimen  measures  five  and  one-half  lines  in  width,  four  and 
one-half  lines  in  length,  and  three  and  one-half  lines  in  depth.  This  shell 
has  some  resemblance  to  P.  sub-globosus  of  Meek  and  Worthen,  from  the 
Hamilton  group,  described  in  the  Illinois  Report,  Volume  III.,  but  it  differs 
from  that  species  by  its  smaller  size,  less  gibbosity  and  smaller  number  of 
plications. 

Formation  and  Locality. — Found  in  the  Niagara  rocks,  east  of  Louisville,  in  almost  perfect  speci- 
mens, but  rather  rare.  * 

Pentainerus  knappi.    HALL. 

Plate  XXVIII.,   figures  1,  2,  3  and  4. 

Pent,  knappi,  Hall.     24th  Rep.  N.  Y.  St.  Museum,  p.  184—1872. 
Pent,  knappi,  Hall.     27th  Rep.  N.  Y.  St.  Museum,  pi.  10,  figures  10,  11  and  12—1875. 

Shell  broadly  elliptical,  moderately  gibbous  above,  compressed  in  front ; 
length  about  one-third  greater  than  width,  somewhat  obscurely  trilobate  ;  car- 
dinal line  equal  to  nearly  one-half  the  width  of  the  shell.  Dorsal  valve 
scarcely  smaller  than  the  ventral;  moderately  gibbous  in  the  upper  part, 
broadly  depressed-convex  below  the  middle,  and  spreading  at  the  latero-basal 
margins.  Ventral  valve  a  little  more  gibbous  in  the  part  above  the  middle 
than  the  opposite  valve,  and  less  depressed  in  the  lower  part ;  the  beak  nar- 
rower below  than  the  other  beak,  above  which  it  is  visibly  elevated,  pointed 
and  only  slightly  arched.  Prof.  Hall  in  his  description  states  the  beak  of  the 
ventral  valve  to  be  closely  incurved  upon  the  other  valve  ;  his  figures  on  plate 
10;  in  his  report,  show  it  the  same  way ;  this  is  a  mistake,  caused  by  the  im- 
perfect condition  of  the  specimen  from  which  description  and  figures  were 
made.  At  the  time  when  I  had  my  plates  lithographed  I  had  no  good  speci- 
men of  this  species  in  my  possession,  and  having  then  also  no  access  to  Dr. 
Knapp's  shell,  which  was  absent  from  Louisville,  I  was  compelled  to  copy  Prof. 
Hall's  figures,  carrying  his  mistake  over  on  my  plate.  Since  then  I  have  ac- 
quired several  almost  perfect  specimens  of  P.  knappi,  which  prove  without 
doubt  the  character  of  the  beak  as  stated  by  me. 

Surface  is  covered  with  strong  plications,  which  become  almost  obliterated 
on  the  umbo,  and  which  diverge  and  curve  outward  towards  the  front ;  they 
gire  rounded,  and  bifurcate  repeatedly  with  the  growth,  of  the  shell,  so  that 


56  PALAEONTOLOGY    OF    KENTUCKY. 

there  are  several  times  as  many  at  the  margins  as  at  their  starting.  On  most 
specimens  the  central  plications  form  in  their  basal  half,  by  double  bifurcation, 
fascicles  or  bundles  of  ribs,  such  as  mark  so  prominently  the  surface  of  Spir. 
camerata  of  the  Carboniferous.  These  fascicles  are  only  found  on  the  middle 
lobe  of  the  shell;  the  lateral  lobes  contain  only  single  and  much  finer  plica- 
tions. The  sides  of  the  shell,  along  the  cardinal  line,  and  down  to  the  point 
of  maximum  width  of  the  shell,  have  a  smooth  surface. 

Concentric  lines  of  growth  cover  the  shell.  This  species  resembles  some- 
what Mr.  Billings'  Stricklandinia  gaspensis,  from  which  it  differs  by  not 
having  any  mesial  depression  or  elevation,  and  no  straight  hinge-extension 
and  narrow  area ;  while  Mr.  Billings'  shell  is  covered,  even  on  the  sides,  by 
plications,  where  P.  knappi  has  a  large,  smooth  lateral  area. 

Prof.  Hall  says  that  this  shell  resembles,  in  every  feature  except  the  strongly 
radiated  surface,  Pentamerus  oblongus,  and  he  does  not  doubt  the  possibility 
that  intermediate  forms  may  be  found  to  connect  the  two  species.  It  can  not 
be  disputed  that  this  shell  greatly  resembles  some  of  the  broader  forms  of  Pent, 
oblongus,  from  which  it  certainly  branched  off  by  evolution,  and  I  feel  certain 
that  it  will  maintain  its  specific  character. 

Formation  and  Locality. — Found  in  the  Niagara  rocks  in,  the  quarries  east  of  the  city  of  Louisville, 
Ky.,  where  it  is  not  very  rare,  at  least  not  in  fractional  shells;  while  perfect  individuals  are  exceedingly 
seldom.  Prof.  Hall  named  this  species  in  honor  of  the  late  Dr.  James  Knapp,  of  Louisville,  Ky.,  who  first 
discovered  it,  as  he  did  so  many  other  new  species,  belonging  to  the  palseozoic  fauna  of  Louisville's  vicinity. 
Dr.  Knapp  was,  for  many  years,  almost  the  only  collector  of  fossils  of  our  city,  thus  having  the  rare 
opportunity  of  getting  all  the  line  specimens  which  our  many  quarries  around  the  city  and  the  Falls  ot 
the  Ohio  afforded. 

Pentamerus  knotti.    x.  SP. 

Plate  XXXII.,  figures  9,  10,  11  and  12. 

Shell  below  medium  size ;  broadly  ovate,  sub-globose ;  length  and  width 
about  equal ;  hinge-line  shorter  than  the  greatest  width  of  the  shell ;  cardinal 
extremities  rounded  ;  lateral  and  basal  margins  forming  usually  a  regular 
curve,  but  sometimes  the  front  is  slightly  straighter  than  the  sides.  Shell 
very  gibbous  and  surface  plicated.  Ventral  valve  more  gibbous  than  the 
other,  having  its  greatest  convexity  about  the  middle  of  the  valve,  from  where 
it  curves  regularly  to  the  lateral  and  basal  margins,  but  very  abruptly  to  the 
cardinal  area,  with  which  it  joins  without  any  line  of  demarcation ;  about  the 
middle  of  the  valve,  or,  at  least,  below  the  umbo,  the  central  portion  for  the 
extent  of  four  plications  becomes  elevated  above  the  adjacent  surface,  slightly 
increasing  in  height  towards  the  front,  thus  forming  a  mesial  elevation  or  fold  ; 
the  umbo  is  prominent,  and  the  beak  elevated  and  strongly  incurved,  but  not 
overlapping  the  umbo  of  the  dorsal  valve ;  the  cardinal  area  is  not  defined  in 


FOSSILS    OF    THE    SILUEIAN    AND    DEVONIAN    ROCKS.  57 

its  margins,  as  it  curves  into  the  general  surface  of  the  valve ;  the  triangular 
fissure  is  either  open  from  cardinal  line  to  apex,  or  partly  closed  by  beaks  of 
both  valves.  Dorsal  valve  less  convex  than  ventral ;  greatest  convexity  at  the 
umbo,  sloping  from  there  in  a  gentle  curve  to  the  sides  and  front,  but  more 
rapidly  to  the  cardinal  line  ;  about  the  middle  of  the  valve  a  depression  sets 
in,  extending  in  width  over  three  plications;  it  increases  in  depth  but  very 
slightly  up  to  the  front,  where  it  forms  a  small  basal  extension,  which 
deflects  downwards  to  meet  the  small  indentation  of  the  other  valve.  In  some 
specimens  no  basal  extension  exists,  or  is  so  small  as  not  to  be  noticed  ;  umbo 
prominent,  and  beak  strongly  incurved  below  that  of  the  other  valve  into  the 
fissure  of  the  latter.  Surface  marked  by  from  ten  to  twelve  rounded  or  sub- 
angular  plications,  which  are  plainly  visible  at  the  lateral  and  basal  margins, 
but  become  obsolete  before  reaching  the  umbo  on  both  valves.  The  specimen 
illustrated  represents  about  the  largest  size  which  this  species  ever  attains. 

Formation  and  Locality. — Occurs  in  the  upper  strata  of  the  Niagara  rocks  in  the  quarries  east  of 
the  city  of  Louisville,  Ky.,  where  it  is  not  very  rare.  I  name  this  species  in  honor  of  W.  T.  Knott,  of 
Lebanon,  Ky.,  the  efficient  Assistant  Geologist  of  our  State,  who  made  us  acquainted  with  the  geology  of 
his  district, 

Pentamerus  knighti.    SOWSKBY. 

Plate  XXIX.,  figures  1,  2  and  17. 
Pentamerus  knighti,  Sowerby.     Min.  Couch.,  Vol.  I — 1812. 

Shell  of  medium  size,  sub-ovate  and  very  gibbous ;  narrow,  with  its  greatest 
width  at  the  base,  which  is  regularly  carved.  Depth  about  four-fifths  of  its 
length.  Surface  plicated. 

Ventral  valve  about  twice  as  deep  as  the  other,  very  gibbous,  and  regularly 
arched  from  beak  to  front.  From  the  longitudinal  center  line  on  the  summit 
of  the  valve  it  curves  for  a  certain  distance,  about  half  way,  gently  and  regu- 
larly towards  the  lateral  margins,  then  it  slopes  very  abruptly  towards  the 
cardino-lateral  angle,  where  it  forms  on  each  side  of  the  beak  a  large  concave, 
smooth  field.  The  umbo  is  narrow  but  very  prominent ;  the  beak  strongly 
arched  over  the  umbo  of  the  other  valve,  but  not  touching  it.  Dorsal  valve 
less  gibbous  than  the  other  valve,  regularly  curved  from  beak  to  front,  and  also 
towards  the  lateral  margins,  except  in  a  small  strip  at  those  margins,  where  the 
valve  deflects  abruptly  downwards,  joining  the  smooth  concave  field  of  the  other 
valve  by  a  similar  but  considerably  smaller  field.  This  valve  is  wider  than  the 
other,  except  at  the  front,  where  both  are  of  equal  width.  The  whole  surface, 
with  the  exception  of  the  above  mentioned  concave  fields  in  the  cardino-lateral 
angles,  is  covered  by  strong,  simple  sub-angular  plications,  reaching  from  beak 
to  front,  and  increasing  as  the  shell  grows  in  strength  or  size  and  in  distance, 

GEOL.    SUR. — 8       •  , 


58'  PALAEONTOLOGY    OF    KENTUCKY. 

There  are  from  twenty  to  twenty- four  ribs  on  each  valve.  Some  concentric 
lines  of  growth  are  visible,  but  whether  the  shell  possessed  other  surface- 
markings  can  not  be  found  out  in  the  silicified  condition  of  the  shells,  inas- 
much as  the  silicification  generally  obliterates  the  finer  striae.  I  have  placed 
these  shells,  of  which  I  possess  only  the  two  individuals  figured  on  plate 
XXIX.,  as  Pent,  knighti,  though  1  have  never  seen  of  that  species  any  correct 
and  detailed  description,  nor  any  reliable  figure,  except  those  in  Ly ell's  Ele- 
ments of  Geology  and  in  Woodward's  Manual  of  the  Mollusca.  I  hope  my 
identification  to  be  correct,  but  if  there  should  be  a  specific  difference,  it  will 
soon  be  found  out  by  geologists,  who  have  access  to  better  libraries  and  muse- 
ums than  the  city  of  Louisville  offers  to  her  scientists. 

Formation  and  Locality. — In  the  Corniferous  rocks  near  Louisville,  in  Kentucky  and  Indiana;  of 
exceedingly  rare  occurrence.  The  two  specimens  in  my  cabinet,  as  far  as  I  know,  are  the  only  representa- 
tives of  this  species  in  the  seven  or  eight  collections  of  the  Falls  Cities,  as  Louisville,  Jeffersonville  and 
New  Albany  are  often  collectively  named. 

Fentamerus  littoni.    HALL. 

Plate  XXVII.,  figures  12  and  13. 

Pentamerus  littoni,  Hall.    Pal.  N.  YM  Vol.  3,  page  262. 
Penlamerus  littoni,  Hall.    24th  Kep.  N.  Y.  St.  Mus.,  p.  186—1872. 
Pentamerus  littoni,  Hall.    27th  Kep.  N.  Y.  St.  Mus.,  pi.  10,  figs.  8  and  9—1875. 

Shell  ovoid,  somewhat  elongate.  Dorsal  valve  moderately  and  regularly 
convex  from  base  to  umbo ;  beak  strongly  incurved  under  the  beak  of  the 
opposite  valve.  Ventral  valve  very  gibbous ;  beak  sub-attenuate,  incurved. 

Surface  marked  by  about  eighteen  to  twenty  and  more  simple,  sub -angular 
plications.  There  is  a  broad,  concave,  smooth  space  on  each  side  below  the 
beak  of  the  ventral  valve,  and  a  much  narrower  space  on  each  side  of  the 
dorsal  valve.  (Hall.)  A  large  specimen  of  this  species,  in  my  cabinet,  meas- 
ures eleven  lines  in  length,  about  the  same  in  width,  and  nine  lines  in  thick- 
ness. 

My  figure  is  a  copy  of  Prof.  Hall's  figure  in  the  27th  Eeport.  At  the  time 
when  my  plates  were  made  I  had  no  fit  specimen  to  copy,  and  Dr.  Knapp's 
shell  was  absent  from  the  city.  This  species  is  associated  with,  and  probably 
related  to,  Pent,  nysius. 

Formation  and  Locality. — It  occurs  in  the  Niagara  rocks  near  Louisville,  Ky.,  where  it  is  one  of 
the  rarest  species.  At  present  my  cabinet  contains  several  fair  specimens. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  53 

Fentamerus  nucleus.    HALL. 

Plate  XXVII.,  figures  25  26  and  27,  and  Plate  XXXIII.,  figures  27,  28,  29,  31,  32  and  33. 
Pentamerus  nucleus,  Hall.     24th  Rep.  N.  Y.  St.  Mus.,  p.  200a— 1872. 
Pentamerus  nucleus,  Hall.     27th  Rep.  N.  Y.  St.  Mus.,  pi.  9.,  figs.  30  to  32—1875. 

Shell  of  medium  size,  sub-globose ;  in  the  typical  specimens  width  and 
length  about  equal,  but  in  the  shells  represented  by  figures  81,  32  and  33, 
on  plate  83,  the  length  exceeds  the  width  considerably.  Ventral  valve  con- 
siderably larger  than  the  dorsal,  and  very  ventricose ;  cardinal  margins 
strongly  rounded,  forming,  in  most  specimens,  a  regular  curve,  which  joins 
the  somewhat  stronger  curve  of  the  lateral  margins.  In  some  shells,  however, 
the  cardinal  margin  is  almost  straight,  equalling  the  greatest  width  of  the 
shell,  and  making  the  cardinal  extremities  either  only  slightly  rounded  or 
obtuse  angular,  as  may  be  seen  in  fig  31,  plate  33.  The  umbo  is  very  promi- 
nent, and  the  beak  strongly  incurved  over  a  small  triangular  foramen.  The 
middle  of  the  valve,  from  below  the  umbo  to  the  front,  is  slightly  elevated, 
forming  a  small  mesial  fold,  and  which  consists  usually  of  two,  but  sometimes 
of  three  elevated  plications.  Dorsal  valve  transversely  elliptical,  or  sub-oval, 
only  moderately  convex ;  umbo  somewhat  inflated.  The  middle  of  the  valve, 
below  the  umbo,  depressed,  forming  a  mesial  sinus,  which  contains  one  or  two 
plications ;  the  beak  is  small  and  strongly  incurved  into  the  opposite  valve. 
Surface  is  marked  by  angular  plications,  usually  two  on  each  side  of  the  mesial 
fold  or  sinus  ;  these  ribs  do  not  reach  very  far  back,  never,  or  very  seldom,  ex- 
tending beyond  the  middle  of  the  valve,  and  in  most  specimens  only  noticeable 
at  and  near  the  margin  of  the  base.  This  species  resembles  somewhat  Pent, 
galeatus  of  the  Lower  Helderberg  group,  especially  in  those  forms  as  repre- 
sented by  figure  31,  plate  33,  but  it  differs,  in  its  shape  and  in  the  arrangement 
of  its  plications,  sufficiently  from  that  species  to  be  distinguished  from  it  at  the 
first  glance.  It  occupies  an  intermediate  position  between  Pent,  galeatus  of 
the  Lower  Helderberg,  and  Pent,  fornicatus  of  the  Clinton  group.  In  regard  to 
the  shells  figured  on  plate  33,  figures  31,  32  and  33,  and  even  those  figured  on 
same  plate,  figures  27,  28  and  29,  I  was  uncertain  for  some  time  whether  to 
place  them  with  this  species  or  to  refer  them  to  Pent,  galeatus.  Since  then  I 
found  specimens  of  intermediate  forms,  uniting  said  shells  with  the  typical 
Pent,  nucleus. 

Formation  and  Locality. — These  shells  are  found  in  the  Niagara  rocks  of  the  quarries  east  of  the 
city  of  Louisville.    Several  good  specimens  were  found  by  different  collectors. 


$0  PALEONTOLOGY    OF    KENTUCKY. 

Pentamerus  nysius,  var.  crassicostus.     HALL. 

Plate  XXVIII.,  figures  5,  6,  7  and  8. 

Pentamerus  nysius,  var.  crassicostus,  Hall.     24th  Kep.  N.  T.  State  Mus.,  p.  184. 
Pent,  nysius,  var.  orassicostus,  Hall.    27th  Kep.  N.  Y.  St.  Mus.,  pi.  10,  figs.  4  and  7—1875. 

Shell  large,  at  least  above  the  medium  size ;  sub- triangular  or  sub-quadrate, 
sometimes  becoming  obscurely  trilobate  ;  length  always,  or  mostly,  exceeding 
the  width.  Ventral  valve  gibbous  ;  greatest  convexity  below  the  umbo,  from 
where  it  curves  gently  to  the  front,  and,  at  first  slightly  and  later  abruptly,  to 
the  lateral  margins  from  apex  to  the  front.  This  abruptly  bent  portion  of  the 
shell  is  always  smooth.  The  beak  is  strong  and  pointed,  and  arched  over  a 
large  open  fissure  ;  it  is  considerably  elevated  over  the  umbo  of  the  other 
valve.  This  valve  has  its  surface  divided,  by  two  prominent  concentric  lines  of 
growth,  into  three  zones,  all  of  which  are,  however,  covered  by  the  radii.  On 
some  of  the  shells  belonging  to  this  species  these  zones  are  not  noticeable.  The 
dorsal  valve  is  less  convex  than  the  other,  it  is  depressed  convex,  with  its 
maximum  convexity  at  the  umbo,  from  where  it  slopes  in  a  gentle  curve  to  the 
anterior  and  lateral  margins.  A  strip  on  its  lateral  margins  is  abruptly  bent 
towards  the  ventral  valve,  and  is  not  covered  by  radii ;  the  umbo  is  regularly 
curved  and  reaching  into  the  fissure  of  the  opposite  valve. 

The  surface  is  covered  by  single,  strong  and  rounded  plications,  numbering 
from  twenty  to  twenty-five. 

Formation  and  Locality. — Occurs  somewhat  abundantly  in  the  Niagara  rocks  in  the  quarries  east 
of  the  city  of  Louisville,  Ky.;  but  well  preserved  specimens  are  rather  rare.  In  my  own  cabinet  there  are 
some  very  perfect  specimens  of  this  species. 

Pentamerus  nysius,  var.  tenuicostus.    HALL. 

This  variety  agrees  in  every  essential  point  with  the  preceding  one,  with  the 
exception  of  the  radii.  These  are  strong  and  coarse  in  the  latter,  and  fine  and 
more  numerous  in  the  present  variety.  The  number  of  costae  never  exceeds 
twenty-five  in  P.  crassicostus,  while  in  P.  tenuicostus  it  is  about  forty. 

Formation  and  Locality. — Found  associated  with  the  preceding  variety  in  the  Niagara  rocks  easl 
of  the  city  of  Louisville,  Ky. ;  somewhat  rarer  than  the  former. 

Pentamerus  oblongus.    SO-WERBY. 

Plate  XXXIII.,  figures  16,  16  and  17. 
Pent,  oblongus,  Sowerby.     Murch.  Sil.  Syst.,  p.  641 — 1839. 
Pent,  laems,  Ibrid.    Iden,  pi.  19,  fig.  9. 

Pent,  oblongus,  Hall.     Geol.  Rep.  of  4th  Dist.  N.  Y.,  p.  7—1843. 
Pent,  oblongus,  Hall.     Pal.  N.  Y.,  Vol.  II.,  p.  79,  pis.  25  and  26. 

Shell  sometimes  very  large,  but  very  variable  in  size  and  form.     It  would  be 


DOSSILS    OF    THE    SlLURlAft    AND    DEVONIAN    BOOKS.  61 

impossible  to  describe  minutely  every  possible  form  of  this  species ;  I  shall, 
therefore,  limit  myself  here  to  the  description  of  the  forms  occurring  in  the 
vicinity  of  Louisville,  which  are  represented  on  plate  XXXIII.  Shell  of 
medium  size,  longitudinally  sub-elliptical  or  sub-quadrate  ;  somewhat  gibbous 
in  the  upper  portion,  but  depressed-convex  towards  the  front ;  trilobate,  the 
middle  lobe  largely  extending ;  beak  of  the  ventral  valve  elevated  above  and 
incurved  upon  the  umbo  of  the  dorsal  valve ;  both  valves  almost  equally  con- 
vex and  their  surface  marked  by  concentric  lines  of  growth,  of  which  some  are 
very  fine  and  scarcely  noticeable,  others,  however,  very  strong  and  dividing  the 
surface  into  different  zones.  The  beak  of  the  dorsal  valve  incurves  into  the 
other  valve  below  its  beak.  All  the  specimens  in  my  cabinet  are  casts ;  some 
of  them  show  undoubtedly,  though  only  faintly,  traces  of  longitudinal  striae 
on  the  middle  lobe  of  both  valves. 

An  individual  of  average  size  has  the  following  dimensions :  length,  two 
inches  and  one-quarter ;  width,  one  inch  and  three-fourths,  and  thickness  about 
one  inch. 

Formation  and  Locality. — Found  in  great  abundance  in  the  lower  strata  of  the  Niagara  and  in  the 
Clinton  group,  in  Jefferson  county,  Ky.,  eastward  from  the  city  of  Louisville.  Though  fractional  shells  of 
this  species  are  numerous,  well  preserved  or  even  fair  specimens  are  rare. 

Pentamerus  oblongus,  var.  cylindricus.    HALL  AND  WHITFIELD. 

Plate  XXX.,  figures  2,  3  and  4. 

Pent,  oblongus,  var.  cylindricus,  H.  and  W.     24th  Kep.  N.  Y.  State  Museum,  pi.  183 — 1872. 
Pent,  oblongus,  var.  cylindricus,  H.  and  W.     27th  N.  Y.  State  Museum,  pi.  10,  figs.  13  and  14—1876. 

Shell  of  medium  size,  sub- cylindrical  in  form;  length  exceeding  the  width 
almost  three  times;  very  gibbous  in  the  upper  portion,  gradually  decreasing 
towards  the  front.  Ventral  valve . a  little  more  convex  than  the  other;  beak 
elevated  above  and  arched  over  the  umbo  of  the  other  valve;  greatest  convexity 
a  little  above  the  middle,  from  where  it  curves  regularly  towards  beak  and 
front,  but  sloping  abruptly,  almost  in  a  straight  line,  to  the  lateral  margins. 
The  trilobate  character  of  Pent,  oblongus  is  very  slightly  noticeable.  Dorsal 
valve  less  convex  and  more  regularly  curved  gently  to  beak  and  front,  more 
rapidly  to  the  lateral  margins ;  beak  incurved  into  the  fissure  of  the  other 
valve  below  its  beak.  Surface  of  both  valves  is  divided  into  different  zones  by 
strong  concentric  lines  of  growth.  The  specimen  figured  measures  in  length 
three  inches ;  in  width  one  inch  and  three-eighths ;  and  in  thickness  a  little 
less  than  the  width. 

Formation  and  Locality. — Found  in  the  Niagara  and  Clinton  groups  in  Jefferson  county,  Ky.,  east 
of  the  city  of  Louisville  ;  somewhat  rare. 


62  PALAEONTOLOGY    OF    KENTUCKY. 

PentamerilS  pergibboSUS.      HALL  AKD  WHITFIELD. 

Plate  XXIX.,  figures  23  and  24. 
Pentamerus  pergibbosus,  Hall  and  Whitfield.     Pal.  of  Ohio,  Vol.  II.,  p.  139,  pi.  7,  figures  10  and  11—1875. 

Shell  of  medium  size,  extremely  and  extravagantly  gibbous  •,  proportionally 
very  elongate  from  beak  to  base,  and  very  narrow ;  the  greatest  width  being 
near  the  front,  and  equal  to  only  about  two-thirds  the  depth  of  the  two  valves 
when  united  in  the  broader  specimens,  and  in  some  extravagant  cases  even  less, 
while  the  depth  of  the  united  valves  almost  equals  the  length  of  the  dorsal 
valve.  Beaks  distant  and  strongly  incurved,  that  of  the  ventral  valve  the  most 
prominent  and  narrower  than  the  opposite.  Ventral  valve  more  than  twice 
as  deep  as  the  dorsal  valve;  most  prominent  at  the  umbo,  from  where  it  slopes 
somewhat  gradually  towards  the  front  margin;  triangular  foramen  large, 
higher  than  wide,  partially  filled  by  the  beak  of  the  opposite  valve.  Dorsal 
valve  more  regularly  arcuate  than  the  ventral,  almost  evenly  so,  except  for  the 
constrictions  of  the  surface  by  lines  of  growth  ;  beak  wide,  strongly  incurved 
into  the  foramen  of  the  other  valve.  Surface  of  the  internal  casts,  in  which 
condition  the  specimens  occur,  strongly  constricted  by  concentric  lines  of 
growth,  which  are  placed  at  irregular  distances,  and  often  dividing  the  surface 
into  several  strongly  marked  transverse  zones.  The  interior  of  the  shell  has 
been  characterized  by  large  longitudinal  septa,  as  seen  by  the  cavities  left  in 
the  casts  ;  that  of  the  ventral  valve  extending  fully  to  or  beyond  the  middle  of 
its  length,  while  those  of  the  dorsal  valve  reach  about  two-thirds  of  the  length 
of  the  valve,  in  all  the  specimens  examined,  and  in  one  example  almost  to  the 
front  margin,  and  vertically  to  the  entire  depth  of  the  valve.  The  surface  of 
the  shell,  in  its  original  condition,  has  been  marked  by  fine  radiating  striae, 
which  are  still  visible  on  the  casts  of  some  individuals  near  the  front  of  the 
valves,  although  the  most  of  them  appear  to  be  smooth  except  for  the  concen- 
tric constriction.  This  species  is  most  nearly  related  to  Pent,  occidentalis,  Hall, 
from  the  Onondago  salt  group,  Gait,  Canada  West;  it  differs,  however,  very 
materially  from  that  one  in  the  much  greater  depth  of  the  dorsal  valve,  and  also 
in  the  relative  thickness  of  the  longitudinal  septa,  that  one  having  them  very 
thick  and  strong;  also  in  the  finer  striation  of  the  surface.  From  Pent, 
littoni,  another  closely  allied  species,  it  differs  in  being  more  extravagantly 
gibbous,  and  narrower,  and  in  being  more  finely  striated.  Copied  exactly  from 
Hall  &  Whitfield' s  description  in  the  Ohio  Report,  Vol.  II. 

Good  specimens  in  my  possession  show  also  faint  radiating  striae  in  the  front, 
still  I  doubt  that  the  original  shell  was  covered  with  radii.  I  have,  for  in- 
stance, some  specimens  of  Spir.  radiata,  which,  on  the  larger  portion  of  the 
surface,  retain  the  shell,  while  the  front  part  is  exfoliated.  The  shell-covered 
portion  shows  no  plications  nor  traces  of  them,  while  the  exfoliated  front  is 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  63 

plainly  plicate,  showing  that  striae  or  radii  may  have  been  obliterated  from  the 
surface  of  the  shell,  even  when  internal  casts  bear  undoubted  evidence  of  their 
existence.  Pent,  pergibbosus,  as  found  in  our  quarries,  a  specimen  of  which  is 
copied  on  plate  XXIX.,  can  not  be  confounded  with  other  species  ;  it  must  be 
recognized  at  the  first  glance. 

Formation  and  Locality. — Found  in  the  middle  strata  of  the  Niagara  rocks,  in  our  quarries  east  of 
the  city  of  Louisville,  where  it  is,  however,  exceedingly  rare.  I  am  not  aware  that,  outside  of  the  speci- 
mens in  my  cabinet,  and  those  formerly  owned  by  Rev.  H.  Herzer,  but  afterwards  acquired  by  Prof.  Hall, 
of  Albany,  N.  Y.,  any  others  are  in  existence. 

Pentamerus  uniplicatus.     N.  SB. 

Plate  XXXIII. .figures  25  and  20. 

Shell  below  medium  size ;  sub-triangular ;  width  exceeding  the  length ; 
greatest  width  below  middle  of  shell. 

Ventral  valve  very  convex  or  gibbous,  having  its  greatest  convexity  a  little 
above  middle  of  valve,  from  where  it  slopes  in  a  moderate  but  regular  curve  to 
the  beak,  and  to  the  baso-lateral  margins,  but  very  abruptly  to  the  cardinal 
borders,  which  are  broadly  rounded;  the  baso-lateral  margins  are  regularly 
curved,  and  the  front  is  slightly  sinuate.  The  central  portion  of  the  ventral 
valve  is  somewhat  elevated,  extending  from  beak  to  front,  and  forming  a  mesial 
fold,  which  is  narrow,  and,  in  fact,  not  at  all  elevated  above  the  general  surface 
of  the  valve ;  its  apparent  elevation  is  due  to  two  broad  furrows,  between  which 
it  is  situated.  This  mesial  fold  is  flat  on  top,  and  has  below  the  umbo  a  shallow 
central  depression.  Umbo  is  prominent,  and  beak  elevated  and  incurved.  The 
dorsal  valve  is  moderately  convex  in  the  umbonal  region,  sloping  from  there 
rapidly  to  the  cardinal  lines,  near  which  it  is  slightly  depressed  ;  towards  the 
baso-lateral  margins  dorsal  valve  becomes  flat.  The  middle  portion  of  the 
valve  from  beak  to  front  is  depressed,  forming  a  mesial  sinus,  which  increases 
in  depth  and  width  towards  the  front,  and  which  is  bounded  on  each  side  by 
an  obscurely  marked  plication  ;  this  marginal  rib  is,  however,  only  in  the  basal 
half  of  the  valve  separated  from  the  balance  of  the  surface  by  a  faint  depres- 
sion. The  bottom  of  the  mesial  sinus  is  occupied  by  a  low  rounded  plication, 
which  extends  to  umbo.  The  umbo  is  small,  and  the  beak  pointed  and  in- 
curved. Outside  of  the  ribs  already  mentioned,  and  some  faint  concentric  lines 
of  growth,  there  are  no  other  surface-markings  indicated.  Size  of  shell  is 
shown  in  illustration. 

Formation  and  Locality. — The  specimen  here  described  and  figured  is  the  only  one  so  far  known  to 
me.  I  found  it  in  the  Niagara  rocks  east  of  the  city  of  Louisville,  Ky. 


64  PALAEONTOLOGY    OF    KENTUCKY. 

Pentamems  ventricosus.    Km- 

Plate  XXXIII.,  figures  12,  13  and  14.  » 

Pentamerus  ventricosus,  Hall.     Geol.  Kep.  Prog.  Wis.,  p.  2 — 1860. 
Pent.  (Pentamerella)  ventricosus,  Hall.     20th  Keg.  Kep.,  p.  374—1868. 
Pent.  (Pentamerella)  ventricosus,  Hall.     Ohio  Pal.,  Vol.  II.,  p.  138—1875. 

Shell  of  medium  size,  globose ;  width  and  length  about  equal,  sometimes  a 
little  wider  than  long ;  hinge-line  short,  and  cardinal  extremities  rounded. 
Ventral  valve  greatly  more  convex  than  the  dorsal,  with  a  very  prominent 
umbo,  and  a  strongly  incurved  beak ;  the  middle  of  the  valve  marked  by  a 
broad,  moderately  deep  sinus,  extending  from  beak  to  base,  where  it  forms  a 
basal  extension,  deflecting  upwards  to  meet  a  mesial  indentation  in  the  dorsal 
valve.  Dorsal  valve  most  prominent  at  the  umbo,  from  where  it  runs  in  a 
straight  line  along  the  summit  of  the  mesial  fold  to  the  front ;  on  both  sides  of 
the  mesial  elevation  there  is  a  marked  depression,  formed  by  the  mesial  fold 
and  the  markedly  upwards  turned  lateral  margins ;  beak  small  and  strongly 
incurved  into  the  opposite  valve. 

Surface  of  the  shell  is  marked  by  concentric  undulations  of  growth,  which, 
according  to  Prof.  Hall's  statement,  are  visible  on  the  internal  casts,  but  which 
the  specimens  in  my  possession,  being  casts  of  the  interior,  do  not  show.  In 
my  shells  the  surface  is  entirely  smooth.  Medium  septum  of  the  ventral  valve 
is  very  short.  This  species  is  easily  recognized  by  its  strong  umbo  and  its 
trilobed  appearance  in  a  front  view.  It  differs  from  the  ordinary  forms  of 
Pentamerus  in  having  the  middle  of  its  dorsal  valve  elevated  in  the  form  of  a 
mesial  fold,  while,  in  true  Pentamerus,  the  middle  of  the  dorsal  valve  is  de- 
pressed, forming  a  dorsal  sinus,  with  a  corresponding  elevation  on  the  other  or 
ventral  valve. 

Formation  and  Locality. — Found  very  rarely  in  the  Niagara  rocks  of  the  quarries  east  of  the  city 
of  Louisville,  Ky. 

Genus  Stricklandinia.    Bmings. 

Stricklandia,  Billings.     Can.  Nat.  and  Geol.,  Vol.  4 — 1859. 
Etymology :  Named  in  honor  of  Prof.  Strickland. 

The  name  Stricklandia  having  been  previously  applied  to  a  genus  of  fossil 
plants,  the  author  abandoned  it  and  substituted  Stricklandinia  for  it.  This 
genus  includes  such  shells  as  Pentamerus  lens,  P.  liratus,  and  P.  laevis.  They 
differ  from  the  real  Pentamerus  in  having  the  valves  usually  sub -equal,  and  no 
longitudinal  septa  or  triangular  chamber  in  the  interior  of  the  dorsal  valve. 
Both  valves  have  an  area,  but  in  the  dorsal  it  is  usually  linear,  or  slightly  ex- 
ceeding the  thickness  of  the  shell  in  height.  The  ventral  valve  has  usually  a 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  65 

concave  mesial  sinus  more  or  less  developed,  and  the  dorsal  valve  a  mesial  fold 
corresponding  thereto.  Some  of  the  species,  as  S.  laevis  and  S.  microcamera 
have  the  hinge-line  straight  and  much  extended. 

Stricklandinia  louisvillensis.    N.  SP. 

Plate  XXXIV.,  figures  81,  32,  33  and  34. 

Shell  of  medium  size,  sub-circular  or  sub-elliptical ;  width  greater  than 
length ;  maximum  width,  below  middle  of  shell,  nearer  to  base  than  shown  in 
the  figures  31  and  32;  cardinal  line  straight  on  each  side  of  beaks,  but  deflecting 
somewhat  to  front ;  shorter  than  the  width  of  the  shell,  and  its  extremities 
rounded ;  lateral  margins  almost  straight,  or  only  slightly  curved ;  at  their 
basal  termination  the  shell  attains  its  greatest  width  ;  basal  margin  broadly 
curved,  with  the  exception  of  its  central  half,  which  is  somewhat  produced,  and 
forming  a  broad  but  short  linguif orm  basal  extension,  giving  the  shell  a  some- 
what trilobed  aspect ;  both  valves  are  about  equally  convex,  ventral  umbo  a 
little  more  than  dorsal ;  umbones  and  beaks  are  so  slightly  developed  as  to  give 
only  a  very  moderate  angulation  to  cardinal  line  at  its  center.  The  hinge- 
areas  are  almost  concealed  by  the  close  approximation  of  the  beaks;  that  of 
ventral  valve  shows  a  narrow,  almost  linear  strip  along  its  rounded  margins. 
Neither  of  the  valves  shows  the  least  indication  of  either  mesial  fold  or  sinus, 
and  the  only  point  of  distinction  between  the  two  valves  is  the  umbo  of  the 
ventral  valve,  which  is  slightly  more  convex  than  the  dorsal,  and  which  is  also 
a  little  elevated  above  the  opposite  beak.  The  surface  is  ornamented  by  seven 
low,  rounded  plications  on  each  valve,  which  start  below  the  umbones  and 
extend,  gradually  increasing  in  strength  and  distance,  to  basal  margin  ;  trans- 
versely' they  are  limited  to  middle  lobe  of  shell;  lateral  lobes  and  umbones  are 
entirely  smooth  or  free  from  ribs  ;  this  feature,  and  the  three-lobate  character 
in  the  basal  margin,  are  not  sufficiently  expressed  in  the  figures,  which  also 
show  one  rib  too  much.  Of  the  seven  plications  on  each  valve,  the  central 
three  are  considerably  stronger  than  the  lateral  ones.  The  whole  surface  of 
the  shell  is  covered  by  fine,  closely  set,  concentric  striae  of  growth,  of  which 
a  few  are  slightly  stronger  than  the  balance,  dividing  the  surface  into  several 
concentric  zones  ;  there  are  also  radiating  lines  visible  which  are  still  finer  than 
the  concentric  striae.  This  shell  bears  some  resemblance  to  Stricklandinia 
davidsoni  of  Billings,  as  figured  and  described  by  him  in  his  "Palaeozoic 
Fossils,  Vol.  II.,"  but  it  differs  from  that  species  by  having  its  greatest  dimen- 
sion transversely,  while  the  other  shell  measures  most  longitudinally ;  in  our 
specimen  the  middle  lobe,  or  the  basal  extension,  is  broader  in  proportion  to  the 
whole  width  of  the  front,  but  considerably  shorter  than  that  of  Str.  davidsoni ; 
and  the  most  prominent  points  of  distinction  are  the  plications,  which  in  S. 

GEOL.   SUB. — 9 


66  PALAEONTOLOGY    OF    KENTUCKY. 

davidsoni  are  only  faintly  developed,  but  covering  the  whole  surface,  while  in 
our  specimen  the  ribs  are  well  marked  and  limited  to  the  central  lobe.  The 
specimen  from  which  the  illustrations  are  made  is  the  only  one  so  far  known 
to  me  ;  it  is  a  well  preserved,  beautiful  shell. 

Formation  and  Locality. — I  found  it  in  the  strippings  of  one  of  the  quarries  east  of  the  city  of 
Louisville,  in  clay  belonging  to  the  Niagara  group,  and  associated  with  other  well  known  Upper  Silurian 
shells ;  I  feel,  therefore,  fully  assured  that  it  belongs  to  the  Niagara  fossils. 


Genus  Chonetes.    Fischer. 

Chonetes,  Fischer.     Oryckt.     Moscow — 1837. 
Etymology :  chone,  a  little  cup. 

Shell  semi -ova1  or  transversely  oblong,  with  a  wide  straight  hinge-line.  Ex- 
ternal margin  of  area  of  ventral  valve  furnished  with  a  row  of  tubular  spines. 
Surface  radiately  striated,  often  spinose.  Foramen  in  the  ventral  area  distinct, 
but  partly  closed  by  a  pseudo-deltidium.  Valves  articulated  by  teeth  and 
sockets.  Dorsal  valve  with  a  cardinal  process,  which  is  simple  at  the  base, 
but  bifid  or  grooved  at  the  extremity.  Interior  of  the  shell  pustulose  or  papil- 
lose. The  genus  Chonetes  is  nearly  allied  to  Productus,  from  which  it  is  dis- 
tinguished by  its  articulated  valves  and  row  of  tubular  spines  on  the  margin  of 
the  ventral  area,  as  well  as  by  other  characters  of  less  importance.  Unfortu- 
nately the  spines  are  often  missing,  having  become  obsolete  by  wear  and  rub- 
bing. Even  in  the  absence  of  these  spines,  Chonetes  may  be  distinguished 
from  Producta  by  their  less  gibbous  and  ventricose  ventral  valve,  and  by  their 
finer  surface  striation.  On  the  other  hand,  Chonetes,  in  form  and  external 
appearance,  makes  an  approach  to  the  genera  Strophomena  and  Leptaena,  and 
may  be  regarded  as  connecting  link  between  the  Sirophomenidae  and  Pro- 
ductidae, 

Chonetes  acutiradiata.    HALL. 

Plate  XVIII.,  figures  18,  19  and  20. 

Strophomena  acutiradiata,  Hall.  Geol.  Rep.  4th  dist.  N.  Y. — 1843. 
Chonetes  acutiradiata,  Hall.  Tenth  Eep.  on  St.  Cab.,  p.  117 — 1857. 
Chonetes  acutiradiata,  Hall.  Pal.  N.  Y.,  Vol.  IV.,  p.  120—1867. 

Shell  of  large  size  in  its  genus  ;  semi-circular ;  sometimes  more  than  twice  as 
wide  as  long ;  the  cardinal  extremities  produced  and  sometimes  very  mucro- 
nate.  Ventral  valve  moderately  convex,  sometimes  a  little  gibbous  in  the 
upper  part,  and  frequently  flattened  or  depressed  at  and  below  the  middle; 
greatest  convexity  a  little  above  the  middle,  from  whence  it  curves  gently  to 
the  front,  somewhat  abruptly  depressed  towards  the  cardinal  extremities, 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  6t 

which  are  sub-auriculate  and  flat  or  slightly  concave;  umbo  moderate,  and 
beak  small  and  pointed,  little  elevated  above  the  hinge-line,  but  perceptibly 
incurved  over  ^the  latter ;  hinge-area  small,  but  increasing  towards  the  beak, 
and  concave.  Dorsal  valve  concave,  corresponding  in  its  general  form  with 
the  convexity  of  the  other  valve ;  hinge  area,  small  and  narrow,  almost  linear ; 
no  beak  perceptible. 

The  surface  of  the  ventral  valve  is  covered  by  peculiar  radiating  striae, 
which  are  strong,  rounded  or  subangular,  and  simple  in  the  umbonal  region, 
outside  of  which  they  bifurcate  and  increase  also  by  implantation,  but  all 
the  striae  on  the  marginal  part  are  greatly  finer  than  the  umbonal  ones ; 
within  the  cardinal  angles  and  along  the  cardinal  margins  the  striae  becomes 
very  irregular  and  often  entirely  obsolete.  Hinge-line  marked  on  each  side 
of  the  beak  by  four  or  five  strong,  tubular  spines,  which  are  directed  obliquely 
outwards.  In  the  specimen  before  me,  which  completely  agrees  in  all  other 
points  with  Prof.  Hall's  description,  neither  these  spines  nor  any  marks  of 
their  former  existence  are  seen ;  it  is  possible  they  became  obliterated  by  the 
process  of  silicification. 

Formation  and  Locality. — Found  in  the  rotten  hornstone  in  the  upper  strata  of  the  Devonian  for- 
mation, at  the  Falls  of  the  Ohio,  on  the  Indiana  shore  of  the  river.  Good  or  perfect  specimens  are  ex- 
tremely rare. 

Chonetes  subquadrata.    x.  SP. 

Shell  as  chonetes  of  medium  size  ;  sub-quadrate,  hinge-line  somewhat  shorter 
than  the  greatest  width  of  shell ;  cardinal  extremities  rounded ;  lateral  mar- 
gins slightly  curved,  almost  straight,  except  in  their  basal  part,  which  is  regu- 
larly curved  into  the  basal  margin ;  central  half  of  front  is  straight  or  only 
slightly  curved. 

Ventral  valve  only  moderately  convex  in  its  central  portion,  which  curves 
regularly  from  its  middle  to  apex  and  base  ;  the  slope  towards  the  lateral  and 
cardinal  margin  is  more  abrupt,  causing  a  flattening  of  the  valve  along  the 
lateral  borders,  and  producing  between  the  cardinal  extremities,  which  are  a 
little  deflected,  and  the  umbo,  a  shallow  concavity  ;  umbo  sharply  defined, 
and  moderately  elevated ;  the  beak  small,  pointed,  and  incurved  over  the 
hinge-area  ;  the  area  is  small,  forming  a  low  triangle,  which  is  divided  by  a 
small  triangular  fissure ;  the  foramen  is  partly  closed  by  the  cardinal  process 
of  the  opposite  valve.  The  margins  of  the  cardinal  area  are  provided  with  two 
round,  tubular  spines  on  each  side  of  the  beak,  which  appear  from  their 
stumps  to  have  an  outward  direction.  The  dorsal  valve  is  concave,  correspond- 
ing in  its  depression  with  the  convexity  of  the  ventral  valve ;  its  hinge-area  is 
narrow  or  linear. 

The  surface  of  both  valves  is  covered  by  fine  rounded,  or  sub-angular  radi- 


68  PALAEONTOLOGY    OF    KENTUCKY. 

ating  striae,  which  increase  partly  by  intercalation  but  mostly  by  bifurcation 
on  the  ventral  valve,  while  it  is  the  reverse  on  the  dorsal  valve,  where  very 
few  of  the  striae  dichostomize,  but  a  great  many  short  ones  are  implanted. 
The  specimen  before  me,  the  only  one  so  far  known,  measures  seven  and  one- 
half  lines  in  width,  live  and  one-half  lines  in  length,  and  two  lines  in  depth. 
It  differs  from  the  other  shallow  Chonetes  by  its  greater  size,  and  from  the 
larger  species  by  its  shallowness. 

Formation  and  Locality. — Found  in  the  'rotton  hornstone  in  upper  strata  of  the  Devonian  forma- 
tion, at  the  Palls  of  the  Ohio,  on  the  Indiana  shore  of  river. 

Chonetes  yandelliana.    HALL. 

Plate  XVII.,  figures  16,  17,  18  and  19,  and  Plate  XXXI.,  figures  20  and  30. 
Chonetes  yandelliana,  Hall.     Tenth  Rep.  on  State  Cabinet,  p.  118 — 1857. 
Compare :  Chonetes  lineata,  ut  sup.,  page  121. 
Chonetes  yandelliana,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  page  123—1867. 

Shell  very  small,  semi-oval,  more  or  less  gibbous ;  hinge-line  equalling  the 
greatest  width  of  the  shell ;  cardinal  extremities  angular,  but  sometimes 
rounded. 

Ventral  valve  regularly  convex,  having  its  greatest  convexity  below  the 
umbo  of  the  valve,  from  where  it  slopes  in  a  regular  curve  to  the  lateral  and 
basal  margins,  but  more  abruptly  to  the  cardinal  angles,  which  are  slightly 
deflected,  forming  there  a  faint  incurvation  or  concavity  ;  beak  small  and  little 
curved. 

Dorsal  valve  corresponding  in  its  concavity  with  the  convexity  of  the  ven- 
tral, but  owing  to  the  internal  cavity  of  the  shell  being  somewhat  less  than 
the  ventral  convexity.  Cardinal  area  of  the  ventral  valve  parallel  with  the 
longitudinal  axis  of  the  shell,  nearly  twice  as  wide  in  the  middle  than  at  its 
extremities ;  foramen  comparatively  large,  with  margins  projecting  and  the 
opening  filled  by  the  cardinal  process  of  the  opposite  valve.  Dorsal  area 
extremely  narrow,  being  barely  a  denned  line.  Surface  marked  by  fine,  almost 
equal  striae,  which  increase  by  bifurcation  and  intercalation  till  there  are  from 
sixty  to  seventy  on  the  margin  of  the  shell.  The  ventral  valve  has  on  its  car- 
dinal margin  three  to  four  short,  oblique  spines  on  each  side  of  the  center. 
The  interior  of  the  ventral  valve  shows  strong,  dental  lamellae,  and  the  muscu- 
lar impressions  are  pretty  well  defined.  The  dorsal  muscular  impression,  are 
also  well  marked,  and  between  them  there  is  a  strong  mesial  ridge,  which  is 
extended  in  a  bidentate  cardinal  process.  The  lower  half  of  the  surface  is 
strongly  papillose.  This  species  bears  a  close  resemblance  to  C.  lineata,  but 
it  is  less  gibbous,  and  not  flattened  on  the  middle  of  the  ventral  valve ;  while 
the  interior  presents  more  strongly  defined  markings.  Generally  three  spines 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  60 

are  noticed  on  each  half  of  the  cardinal  margin,  but  this  is  subject  to  varia- 
tion, as  the  number  may  differ  from  two  to  four.  Figure  19,  plate  17,  is 
enlarged,  and  figures  19  and  20,  on  plate  31,  show  an  elongate  form. 

Formation  and  Locality.— Occurs  in  the  hydraulic  limestone,  in  Jefferson  county,  Ky.,  and  in 
Clark  county,  Indiana,  and  is  somewhat  abundant  in  well  preserved  specimens.  Prof.  Hall  named  this 
species  in  honor  of  the  late  Dr  Lunsford  Yandell,  Sr.,  of  Louisville,  Ky.,  who  was  one  of  the  first  col- 
lectors of  fossils  from  the  Falls  of  the  Ohio. 

Genus  Productella.    Han. 

Productella,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  page  153—1867. 
Etymology .  Productella,  diminutive  of  Productus. 

Shell  having  the  general  form  of  Productus,  but  uniformly,  with  a  narrow 
area  on  each  valve,  a  foramen  or  callosity  on  the  ventral  area,  small  teeth,  and 
more  or  less  distinct  teeth-sockets.  The  reniform  vascular  impression,  rising 
from  between  the  anterior  and  posterior  muscular  impressions,  curves  gently 
outwards,  and  following  a  curvature  [somewhat  parallel  with  the  margin  of  the 
shell  to  below  the  middle  of  its  length,  is  abruptly  recurved  and  the  extremity 
turned  a  little  backwards,  terminates  about  half  way  between  margin  and 
anterior  extremity  of  mesial  septum.  The  cardinal  process,  seen  from  the 
inner  side,  is  bilobed,  and  from  the  exterior  side  each  of  these  divisions  is 
usually  bilobed.  These  shells  differ  from  Stropholosia  in  the  extremely  narrow, 
linear  cardinal  area,  greater  extension  of  hinge-line,  more  extreme  arcuation 
or  ventricosity  of  ventral  valve  in  many  or  most  of  the  species,  and  especially 
in  the  direction  and  termination  of  the  reniform  vascular  impressions,  which 
resemble  those  of  Aulosteges,  and  of  some  of  Productus.  It  differs  from  Pro- 
ductus by  the  constant  presence  of  an  area,  hinge-teeth  and  sockets. 

Productella  subaculeata  var.  cataracta.    HALL  AND^WHITJ-IELD 

Plate  XVII.,  figures  6  to  9. 

Productella  subaculeata  var.  cataracta,  H.  and  W.     24th  Regent's  Keport,  p.  198 — 1872. 
Productella  subaculeata  var.  cataracta,  H.  and  W.     27th  Regent's  Rep.,  pi.  9 — 1875. 

Shell  small,  semi-globose,  rounded;  hinge-line  straight  and  about  equal  to 
width  of  shell;  length  and  width  of  shell  about  equal.  Ventral  valve  very 
gibbous,  regularly  curved  from  umbo  downward,  and  also  transversely ;  umbo 
is  considerably  elevated  above  hinge-line,  and  the  beak  is  small  and  incurved. 
The  lateral  margins  form  with  the  cardinal  line  nearly  right- angles;  they  are 
a  little  contracted  below  the  extremities,  forming  small  ears ;  below  the  ears 
the  sides  are  regularly  curved,  and  the  front  is  broadly  rounded.  The  dorsal 
valve  is  deep  concave,  as  shown  in  the  specimen  illustrated  on  plate  17,  figures 
5  and  6.  Said  specimen  is  nearly  perfect  in  both  valves,  and  entirely  free  from 


76  PALEONTOLOGY    OF    KENTUCKY. 

rock.     In  this  shell  the  dorsal  valve  shows  a  regular  deep  concavity,  into  which 
the  beak  of  the  ventral  valve  overlaps. 

The  greatest  depth  of  the  dorsal  concavity  is  about  equal  to  half  the  length 
of  the  hinge-line ;  below  the  beak  there  is  a  slight  impression  into  the  umbo 
of  the  other  valve.  The  surface  is  ornamented  by  low,  rounded,  radiating 
striae,  reaching  almost  to  the  beak.  My  specimen,  before  alluded  to,  shows 
real  continuous  plications,  not  mere  isolated  elevations  above  and  near  the 
bases  of  each  spine.  Even  the  dorsal  valve  has  faint  indications  of  corres- 
ponding striae.  On  these  radii  are  placed  at  irregular  intervals  the  long, 
slender,  round  spines,  with  which  the  ventral  valve  is  closely  covered.  These 
spines  are  only  indicated  on  the  silicified  internal  casts  by  their  scars,  and  on 
better  preserved  shells,  by  their  bases  and  short  stumps ;  they  are  only  pre- 
served in  full  length,  where  even  the  surrounding  matrix  became  silicilied  at 
the  same  time  with  the  shell.  Concentric  lines  of  growth  are  seldom  noticed 
on  our  shells. 

Formation  and  Locality. — Occurs  rather  abundantly  in  the  cherty  layers  superimposed  upon  the 
hydraulic  limestone  of  the  Devonian  formation  around  the  Falls  of  the  Ohio,  in  Jefferson  county,  Ken- 
tucky, and  in  Clark  county,  Indiana,  where  it  is  usually  found  as  silicifled  casts  of  the  interior.  "Well 
preserved  shells,  like  that  illustrated,  showing  both  valves  in  perfect  condition,  with  the  exception  of  the 
spines,  are  extremely  rare. 

Productella  semiglobosa.     ».  SP. 

Plate  XXVI.,  figure  7. 

Shell  of  medium  size,  semi-globose  or  sub-circular ;  hinge-line  somewhat 
shorter  than  greatest  width  of  shell;  cardinal  extremities  rounded.  Yentral 
valve  very  gibbous,  regularly  curved  from  umbo  to  front,  and  also  trans- 
versely ;  umbo  only  moderately  elevated  above  surrounding  surface  ;  beak 
incurved  upon  hinge-line,  not  overlapping  it  into  dorsal  valve.  Width  and 
length  of  shell  about  equal,  but  sometimes  the  width  exceeding  the  length. 
Dorsal  valve  apparently  deep  concave,  but  its  other  characters  are  not  known. 
Surface  does  not  show  any  markings,  except  the  stumps  of  a  few  isolated 
spines  placed  at  irregular  intervals ;  the  figure  7,  on  plate  26,  shows  about 
twice  as  many  as  in  reality  exist.  I  am  unable  to  identify  it  with  any  of  the 
species  of  Devonian  Productella  known  to  me,  and  I,  therefore,  place  it  in 
the  above  named  new  species.  This  shell  has  some  similarity  with  some 
middle-sized,  but  very  ventricose  forms  of  Strophodonta  demissa,  from  which 
it  is,  however,  easily  distinguished  by  its  smooth  surface,  which  shows  only  a 
few  spine-bases,  while  the  Strophodonta  demissa  is  covered  by  radiating  striae, 
and  never  becomes  fully  as  ventricose  as  our  shell.  The  specimen  illustrated 
is  of  about  average  size. 

Formation  and  Locality. — Occurs  in  the  Corniferous  limestone  at  and  around  the  Falls  of  the  Ohio, 
in  Kentucky  and  Indiana.  Only  a  few  specimens  are  so  far  found. 


Genus  Leiorhynchus.    Han. 

Leiorhynchus,  Hall.     13th  Regent's  Report — 1860. 
Etymology :  leios,  smooth ;  rhynchos,  a  beak. 

Shell  ovate,  circular  or  transverse,  with  valves  unequally  convex,  and  marked 
by  mesial  sinus  and  fold  in  the  ventral  and  dorsal  valves  respectively.  The 
surface  is  plicated  by  rounded,  bifurcating  ribs,  which  are  always  more  con- 
spicuous on  the  mesial  fold  and  sinus,  whilst  they  often  become  obsolete  on  the 
lateral  portion  of  the  shell ;  concentrically  marked  by  strong  lines  of  growth. 
Substance  of  the  shell  fibrous,  usually  thin.  Valves  articulated  by  teeth  and 
sockets  ;  the  apex  of  the  ventral  valve  perforate  at  some  period  of  its  growth, 
the  lower  side  being  closed  by  deltidial  plates.  On  the  interior  of  the  ventral 
valve,  two  short  diverging  dental  lamellae  extend  into  and  are  joining  the  sides 
or  bottom  of  the  rostral  cavity;  the  muscular  impression  occupies  a  narrow 
triangular  or  ovate  triangular  space,  below  the  dental  lamellae.  The  dorsal 
valve  has  a  well-defined  septum,  often  reaching  below  the  middle  of  the  valve, 
and  divided  above,  leaving  a  triangular  or  spoon-shaped  depression.  The 
hinge-plates  are  narrow,  strong  processes,  with  sockets  embracing  the  teeth 
of  the  opposite  valve.  (Hall.)  This  genus  is  closely  allied  to  that  of  Rhyn- 
chonella. 

Leiorhynchus  quadricostatus.    VANVXKM. 

'    Orthis  quadricostata,  Vanuxem.     Geol.  Rep.  3d  dist.  N.  Y.,  p.  186 — 1842. 
Orthis  quadricostata,  Hall.     Geol.  Rep.  4th  dist.  N.  Y.,  p.  223—1843. 
Leiorhynchus  quadricostata,  Hall.     13th  Rep  on  St.  Cab.,  p.  86 — 1860. 
Leiorhynchus  quadricostata,  Hall.     Pal.  N.  Y.,.Vol.  IV.,  p.  357—1867. 

Shell  of  medium  size ;  broadly  ovate  ;  from  moderately  convex  to  somewhat 
gibbous  ;  with  distinct  mesial  fold  and  sinus. 

Ventral  valve  a  little  gibbous  towards  the  beak;  side  nearly  flat,  with  a 
mesial  sinus  commencing  below  the  umbo  and  extending  to  the  front ;  it  in- 
creases gradually  in  width  and  depth  towards  front ;  umbo  is  of  medium  size, 
and  beak  elevated  and  pointed,  and  slightly  arched  but  not  incurved ;  place  of 
the  apex  appears  to  be  occupied  by  a  round  perforation.  Dorsal  valve  is  more 
convex  than  the  opposite,  having  its  greatest  convexity  in  the  middle  of  the 
valve,  from  where  it  slopes  in  a  light  curve  to  the  baso-lateral  margins,  and  in 
a  stronger  curve  to  the  beak  and  cardinal  margins.  A  mesial  fold  commences 
to  rise  above  the  surface  in  front  of  the  umbo,  from  where  it  slightly  increases 
in  height  and  width  towards  the  front.  The  dorsal  umbo  is  low,  beak  small 
and  incurved.  The  surface  is  partly  plicated.  On  the  mesial  elevation  and  in 
the  mesial  sinus  are  generally  'four  plications  plainly  visible  in  the  basal  half. 


72  PALAEONTOLOGY    OF    KENTUCKY. 

It  appears  that  in  the  umbonal  half  of  the  shell  only  two  plications  existed 
before  they  became  obliterated,  and  that  by  bifurcation  the  four  ribs  were 
produced,  which  now  occupy  sinus  and  fold.  Some  individuals  have  five  ribs 
instead  of  four.  The  lateral  parts  of  this  shell  are  often  covered  with  several 
faintly  visible  plications,  but  in  most  of  the  specimens  these  lateral  ribs  become 
entirely  obsolete,  and  the  surface  outside  of  sinus  and  fold  is  free  from  any 
markings  whatever. 

Specimens  of  this  species  are  seldom  in  a  fair  condition ;  they  are  found  in 
the  Genesee  shale,  and  their  shell  being  very  thin,  they  become  generally  dis- 
torted and  compressed.  The  inclosing  shale  or  slate  did  not  possess  sufficient 
density  and  hardness  to  resist  the  pressure  of  the  superimposed  rocks,  but 
became  compressed  itself,  and  thus  the  imbedded  shells  suffered  the  same  fate 
as  their  matrix.  I  have  found  in  the  shales  at  the  Falls  of  the  Ohio,  on  the 
Kentucky  shore  of  the  river,  an  almost  perfect  specimen  of  this  species,  with 
a  very  slight  distortion,  and  on  the  Indiana  side  I  picked  up  another  shell 
belonging  to  L.  quadricostata,  not  distorted  at  all,  but  a  little  defective  at  the 
front,  which,  however,  was  easily  restored ;  and  thus  I  possess  two  specimens 
which  show  exactly  the  form  and  surf  ace- markings  of  this  species.  Prof. 
Hall  states  in  his  description  of  this  shell,  in  Pal.  N.  Y.,  Vol.  IV.,  page  358, 
that  on  account  of  the  compressed  and  crushed  condition  of  the  fossil,  its  real 
form  and  its  correct  proportions  could  not  be  determined.  The  specimen  before 
me  measures  nine  lines  in  length,  nine  and  one-half  lines  in  width,  and  five  and 
one-half  lines  in  depth.  Another  specimen  found  at  Lexington,  Indiana, 
measures  thirteen  lines  in  length,  one  inch  in  width,  and  seven  to  eight  lines  in 
depth.  These  dimensions  show  that,  in  most  instances,  this  shell  has  its  width 
and  length  about  equal,  while,  its  convexity  may  vary  somewhat ;  its  greatest 
width  is  either  at  the  middle  of  the  shell  or  a  little  below  it. 

Formation  and  Locality. — Found  mainly  in  the  Genesee  shales,  being  the  top  strata  of  the  Devo- 
nian formation,  at  the  Falls  of  the  Ohio,  in  Kentucky,  and  at  Lexington,  Indiana,  but  some  specimens  are 
also  found  in  the  rotten  hornstone  just  below  said  shales. 


Genus  Rhynchonella. 


Fischer. 


Rhynchonella,  Fischer.     Mem.  Soc.  Imp.,  Mosc. — 1809. 
Etymology :  rhynchos,  a  beak ;  ella,  little. 

Shells  trigonal,  acutely  beaked,  usually  plicated,  dorsal  valve  elevated  in 
front,  depressed  at  the  sides.  Ventral  valve  flattened  or  hollowed  along  the 
center;  hinge-plate  supporting  two  slender  curved  lamellae;  dental  plates 
diverging. 

The  foramen  is  at  first  only  an  angular  notch  in  hinge-line  of  the  ventral 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  73 

valve,  but  the  growth  of  the  deltidium  usually  renders  it  complete  in  adult 
shell ;  in  the  cretaceous  species  it  is  tubular.     In  some  species  the  beak  is  so 
closely  incurved  upon  the  other  as  to  allow  no  space  for  a  pedicle. 
The  Rhynchonella  loxia  is  made  the  type  of  the  genus  Rhynchonella. 

Rhynchonella  acinus.    HALL. 

Plate  XXVI.,  figures  6,  13  and  14,  and  Plate  XXXII ,  figures  13  to  16. 
Rhynchonella  acinus,  Hall.     Trans.  Alb.  Inst.,  Vol.  IV.,  p.  215—1863. 

Rhynchonella  acinus,  Hall.     28th  Rep.  N.  Y.  St.  Mus.  Nat.  Hist.,  Mus.  edit.,  p.  163,  pi.  26,  figs.  7-11—1879. 
Rhynchonella  acinus,  Hall,     llth  Geol.  Rep.  of  Ind.,  p.  306—1881. 

Shell  very  small,  longitudinally  ovate,  sub-attenuate  towards  the  beak  and 
truncate  in  front,  valves  sub-equally  convex.  Ventral  valve  sub-arcuate,  flat- 
tened in  the  middle,  below  which  it  is  sinuate ;  beak  incurved.  Dorsal  valve 
somewhat  flattened  in  the  middle,  and  sometimes  a  little  depressed  in  upper 
part  of  median  line,  two  of  the  plications  becoming  elevated  towards  the  front, 
corresponding  to  an  abruptly  depressed  sinus  in  ventral  valve,  in  the  bottom 
of  which  is  a  single  plication  ;  there  are  three  and  rarely  four  plications  on 
each  side  of  mesial  fold  of  dorsal  valve,  and  four  on  each  side  of  the  sinus  of 
the  ventral  valve.  Concentric  lines  of  growth  usually  only  faintly  marked. 
Length  to  width  usually  about  as  four  to  three,  and  depth  about  equal  to 
width,  giving  a  sub-quadrate  transverse  section  ;  average  size  of  the  shell  as 
represented  in  the  figures  on  plate  26. 

This  species  differs  from  Rhyn.  bidentata  of  Hisinger,  in  being  larger,  more 
robust  and  .ventricose,  and  proportionally  more  elongate;  the  plications  are 
more  rounded,  and  the  whole  aspect  of  the  shell  less  angular.  It  approaches 
in  form  the  Rhyn.  bialveata  of  the  lower  Helderberg  formation,  but  it  is 
more  robust,  and  the  plications  are  more  rounded.  (Hall.) 

Formation  and  Locality. — Found  in  the  lower  strata  of  the  Niagara  group  in  the  quarries  east  of 
the  city  of  Louisville,  Ky.,  but  of  rare  occurrence.  On  some  of  the  plates  the  two  lower  figures  of  this 
species  have  no  numbers.  The  side  view  should  be  number  13,  and  the  front  view  number  14.  This  front 
view  shows  in  the  mesial  elevation  three  plications  ;  there  should  be  only  two. 

Rhynchonella  bellaforma.    K.  SP. 

Shell  of  medium  size  ;  sub -triangular  or  sub-pentagonal ;  moderately  convex, 
rather  somewhat  compressed  ;  cardinal  margins  sloping  down  to  the  middle  of 
shell,  and  forming  at  the  beaks  an  obtuse  angle  of  about  one  hundred  degrees ; 
lateral  margins  short  and  strongly  curved ;  base  only  curved  at  the  front 
angles,  the  balance,  about  four-fifths  of  the  whole  front,  almost  straight,  with 
a  slight  emargination  or  inflection  of  its  middle  part.  Width  to  length  as 
three  to  two  ;  greatest  width  below  the  middle. 

Ventral  valve  moderately  convex  at  the  umbonal  region,  and  near  the  cardinal 
and  lateral  margins  ;  in  front  of  the  umbo  the  central  portion  of  the  valve 

OEOL.   8UR. — 10 


74  PALAEONTOLOGY    OF    KENTUCKY. 

becomes  depressed,  which  depression  increases  in  depth,  but  more  rapidly  in 
width,  towards  the  base  or  front,  which  it  occupies  almost  to  the  full  extent  of 
basal  length  ;  umbo  is  small,  and  the  beak  elevated  and  slightly  incurved.  The 
dorsal  valve  is  somewhat  larger  than  the  ventral,  and  also  more  convex ;  it  is 
divided  into  two  halves  by  a  central  depression,  which  extends  f  rom  the  beak 
to  a  point  below  the  middle  of  the  valve,  and  which  is  most  prominent  in 
umbonal  region  ;  it  is  occupied  by  six  single  strong  plications  which  reach 
entirely  back  to  apex. 

The  two  outside  of  these  six  plications  form  the  lateral  limit  of  the  depres- 
sion, which  ceases  a  little  below  the  middle  of  valve,  where  the  said  six 
plications  become  elevated  above  surface,  and  all  six  rising  to  the  same  level 
extend  to  the  front,  where  they  form  a  mesial  fold,  which  is  entirely  flat  on  top  ; 
the  lateral  , portion,  of  the  valve  outside  of  this  mesial  combination  of  sinus 
and  fold,  is  regularly  and  gently  curved  from  beak  to  the  lateral  and  baso- 
lateral  margins,  while  it  slopes  abruptly  towards  the  cardinal  lines,  along  which, 
in  both  valves,  the  borders  are  inflected,  meeting  under  a  very  obtuse  angle, 
but  with  its  apex  outward  ;  these  inflected  borders  are  entirely  smooth ;  the 
umbo  is  small,  also  the  beak,  which  is  incurved  into  the  other  valve.  The 
surface  is  ornamented  by  strong,  rounded,  simple,  radiating  plications,  of 
which  the  ventral  valve  has  seven  in  its  mesial  sinus,  and  five  on  each  side  of 
it ;  while  the  dorsal  valve  has  six  on  its  mesial  fold  and  six  on  each  side  of  the 
same.  All  these  ribs  reach  back  to  the  beak,  and  are  of  about  equal  strength, 
with  the  exception  of  the  two  outside  ones  on  each  side  of  the  mesial  fold  and 
sinus,  which  are  smaller,  and  extend  only  for  some  distance  back  into  the  shell, 
becoming  obliterated  by  the  smooth  cardinal  borders.  No  other  surface-mark- 
ings are  observable.  The  specimen  here  described  measures  :  length,  six  lines  ; 
width,  nine  lines  ;  depth,  three  lines.  This  is  one  of  the  most  beautiful  Rhyn- 
chonella,  as  far  as  its  shape  is  concerned,  and  for  that  reason  I  have  named  it 
bellaforma.  I  do  not  know  any  species  of  its  congeners  to  compare  it  with, 
except,  probably,  Rhyn.  tennesseensis  of  Roemer,  but  not  with  that  form  of 
said  species  which  Prof.  Hall  has,  in  late  years,  placed  in  the  species  of  Rhyn. 
stricklandi.  To  Rhyn.  tennesseensis  it  has  some  resemblance,  but  differs  from 
it  by  its  small  depth,  its  being  more  transverse,  its  smaller  and  more  numerous 
plications,  its  cardinal  borders,  which  are  not  as  much  inflected  as  in  that 
species  ;  in  our  shell  the  marginal  angle  at  said  borders  has  its  apex  outward, 
while  the  same  angle  in  Rhyn.  tennesseensis_  has  its  apex  inward.  But  the 
most  characteristic  feature  of  our  shell  is  its  peculiar  combination  of  mesial 
sinus  and  fold  on  its  dorsal  valve,  by  which  it  is  easily  distinguished  from  any 
other  Rhynchonella. 

Formation  and  Locality. — I  found  this  interesting  shell,  finely  preserved,  in  the  Niagara  clay,  east 
of  our  city.     So  far  this  one  specimen  only  is  known  to  me. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  75 

Rhynchonella  Carolina.    HALL. 

Plate  XIII.,  figures  1,  2  and  3,"34  and  35, 

Rhyn.  Carolina,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  337,  pi.  34,  figs.  14-19—1867. 
Rhyn.  Carolina,  Meek.     Pal.  of  Ohio,  Vol.  I.,  p.  196,  pi.  18,  figs.  8a-e— 1873. 

Shell  of  medium  size,  trigonoid-subovate  in  general  outline,  moderately 
gibbous,  a  little  produced  or  widened  in  front.  In  an  old  shell  of  unusual  size 
belonging  to  my  cabinet,  the  widening  of  the  front  portion  is  very  consider- 
able, so  that  the  lateral  margins,  from  beak  to  a  little  below  the  middle  of  the 
shell,  become  strongly  concave,  while  in  younger  specimens,  those  as  figures  34 
and  35,  said  margins  are  almost  straight. 

Ventral  valve  a  little  less  convex  than  the  other ;  greatest  convexity  at  the 
umbo,  from  where  it  curves  gently  towards  the  front,  and  more  abruptly  to 
the  cardinal  margins;  beak  prominent,  little  curved  or  nearly  straight,  and 
elevated  a  little  above  umbo  of  other  valve. 

Mesial  sinus  starts  a  little  above  the  middle  of  the  valve,  is  broad,  shallow 
and  flat  at  the  bottom  ;  its  margins  are  not  well  defined.  Dorsal  valve  more 
convex,  moderately  gibbous  and  regularly  arcuate  from  summit  to  base,  the 
sides  more  abruptly  curved ;  mesial  fold,  beginning  a  little  above  middle  of 
valve,  is  broad,  slightly  convex,  mostly  flat,  without  well  defined  margins ; 
beak  strongly  incurved  into  the  other  valve. 

Surface  is  marked  by  from  twenty-four  to  thirty  simple,  sub-angular,  radi- 
ating costae,  of  which  from  six  to  eight  occupy  the  mesial  sinus,  and  about 
the  same  number  the  mesial  elevation ;  the  ribs  in  the  sinus  and  on  the  fold 
are  stronger  than  the  lateral  ones.  The  plications  increase  from  the  beak 
towards  the  front  in  size  and  distance,  and  the  lateral  ribs  are  curving  more  or 
less  outwards.  No  other  surface-markings  are  visible,  not  even  concentric  lines 
of  growth,  on  th«  most  perfectly  preserved  shells  in  my  cabinet.  This  species 
differs  from  all  other  rhynchonelloid  forms  of  the  Corniferous  limestone,  by 
its  broad,  shallow  and  poorly  defined  sinus,  as  well  as  by  its  broad,  flat  and 
also  poorly  defined  mesial  elevation,  and  by  its  more  extended  beak.  Prof. 
Hall  is  of  the  opinion  that  a  larger  material  may  hereafter  prove  its  generic 
distinction  from  Rhynchonella. 

Formation  and  Locality. — Occurs  in  the  Corniferous  limestone  at  and  near  the  Falls  of  the  Ohio, 
in  Kentucky  and  Indiana.  It  is  rather  rare,  though  I  possess  in  my  cabinet  a  few  exceedingly  well  pre- 
served specimens  retaining  the  shell  entirely. 


76  PALEONTOLOGY    OF    KENTUCKY. 

Rhynchonella  gainesi.    N.  SP. 

Plate  XXXI.,  figures  6,  7,  8,  and  9. 

Shell  very  small;  sub- triangular ;  length  equal  to  greatest  width,  which 
latter  is  near  the  base ;  the  cardino-lateral  margins  run  in  almost  straight  lines 
from  beak  to  point  of  greatest  width;  basal  margin  broadly  curved,  nearly 
straight.  Shell  concavo-convex,  and  surface  smooth  except  near  the  margins, 
where  faint  plications  are  noticed.  Ventral  valve  moderately  convex  at  its 
umbo,  and  in  its  upper  one-third ;  the  balance  deeply  depressed  to  a  sinus, 
which  occupies  the  whole  width  of  the  valve,  and  which  is  margined  on  each 
side  by  the  lateral  margins  of  the  shell,  which  deflect  here  downwards  to  a 
sharp  prominent  point;  sinus  is  flat  in  the  bottom  and  extends  considerably 
beyond  the  base,  forming  a  quadrilateral  basal  extension,  which  deflects  at 
right-angles  upward  to  tit  into  a  corresponding  indentation  in  the  dorsal  valve  ; 
the  height,  measured  between  the  highest  point  of  the  basal  extension  and  the 
apex  of  the  pointed  margins  of  the  sinus,  is  almost  equal  to  the  width  of  the 
shell ;  the  beak  is  elevated  and  slightly  curved.  Dorsal  valve  is  somewhat 
gibbous,  with  its  greatest  convexity  at  the  middle  of  the  valve,  from  where  it 
slopes  in  strong  curves  to  the  cardino-lateral  and  basal  margins ;  its  central 
portion  runs  in  a  straight  line  from  the  beak  to  the  base,  forming  the  mesial 
fold,  which  becomes  risible  at  a  little  above  the  middle  of  the  valve,  and  in- 
creases rapidly  to  the  front  or  base,  where  it  is  very  prominent ;  umbo  is 
inflated,  and  the  beak  incurved  into  the  opposite  valve.  The  surface  is  en- 
tirely smooth  in  its  upper  half,  while  the  lower  one  shows  some  plications, 
which  are  plainly  visible  at  the  basal  margin,  but  do  not  extend  far  into  the 
shell.  There  are  two  faint  indication,  of  plications  on  each  side  of  the  mesial 
fold  and  sinus,  while  the  mesial  fold  has  three  and  the  sinus  two  ribs  on  its 
summit  or  bottom  respectively.  No  other  surface-markings  are  observable  on 
account  of  the  silicification  of  the  shell. 

Formation  and  Locality. — Found  in  the  rotten  hornstone  of  the  Devonian  formation  exposed  in 
several  washes  in  Jefferson  county,  Ky.  This  pretty  little  shell  is  not  very  rare.  This  species  is  named 
after  Prof.  J.  T.  Gaines,  of  Louisville,  Ky.,  who,  as  ardent  student  and  collector  of  fossils,  deserves  such  a 
recognition. 

Rhynchonella  indianensis.    HALL. 

Plate  XXXIII.,  figures  18,  19  and  20. 

Rhyn.  indianensis,  Hall.    Trans.  Alb.  Inst.,  Vol.  IV.,  p.  215—1863. 

Rhyn.  indianensis,  Hall.     28th  Kep.  N.  Y.  St.  Mus.  Nat.  Hist.,  Mus.  edit.,  p.  163,  pi.  26,  figs.  12-22— 1S76. 
Rhyn.  indianensis,  Hall,    llth  Geol.  Rep  of  Indiana,  p.  306—1881. 

Shell  small,  broadly  ovate  or  sub-triangular;  length  and  width  nearly  equal, 
or  the  former  is  sometimes  slightly  exceeded  by  the  latter.  Cardinal  slopes  in 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  7Y 

the  more  gibbous  specimens  flattened.  Ventral  valve  with  the  beak  pointed 
and  incurved,  depressed-convex  in  the  middle,  and  gradually  becoming 
depressed  and  sinuate  in  front,  two  or  three  of  the  plications  included  in  the 
sinus.  Dorsal  valve  a  little  the  more  gibbous,  somewhat  flattened  in  front  of 
the  umbo.  Three  or  four  of  the  plications  run  straight  from  beak  to  front  and 
form  a  mesial  elevation,  the  lateral  plications  are  curving  outwards  to  the 
lateral  margins.  Each  valve  marked  by  from  nine  to  twelve  rounded  or  sub- 
angular  plications,  which  sometimes  obsolete  toward  the  beak.  The  concentric 
lines  are  very  obscure. 

This  species  resembles  the  Rhyn.  neglecta  of  the  Niagara  group  of  New 
York,  but  it  is  larger  and  more  robust,  with  stronger  and  more  rounded  plica- 
tions. (Hall.) 

Formation  and  Locality. — Found  rarely  in  the  Niagara  strata  in  the  quarries  east  of  the  city  of 
Louisville,  Ky.  Our  specimens  are  smaller  than  the  Waldron  shells,  and  the  plications  on  the  Kentucky 
individuals  are  less  marked.  They  even  become  sometimes  almost  obsolete  on  the  lateral  slopes  of  the 
Shell,  and  seldom  extend  as  far  back  as  the  ribs  on  Waldron  specimens.  , 

Rhynchonellu,  louisvillensis.    K.  SP. 

Plate  XXXI.,  figures  1  to  4. 

Shell  of  less  than  medium  size  among  the  Rhynchonellidae ;  longitudinally 
sub -oval  or  sub-trigonal;  length  and  width  about  equal,  the  latter  rarely  ex- 
ceeding the  former  slightly  ;  both  valves  about  equally  convex. 

Ventral  valve  moderately  convex ;  mesial  sinus  beginning  in  front  of  the 
umbo,  is  broad  and  flat,  deepens  at  the  base,  and  has  a  considerable  quadri- 
lateral extension,  fitting  in  a  corresponding  indentation  of  the  other  valve  ;  it 
contains  five  plications ;  beak  small  and  pointed,  and  only  slightly  arched. 
Dorsal  valve  somewhat  more  convex  than  the  other  ;  mesial  fold  starting  below 
the  umbo,  and  becomes  prominent  at  the  front,  and  contains,  like  the  sinus, 
five  plications  ;  beak  small,  narrow,  and  incurving  into  the  other  valve  beneath 
the  ventral  beak. 

Surface  is  ornamented  by  four  or  five  rounded  ribs  on  each  side  of  the  mesial 
depression  or  elevation;  those  on  the  lateral  slopes  of  the  dorsal  valve  are 
abruptly  curving  outwards  and  downwards.  In  regard  to  measurement,  the 
figures  on  plate  31  give  the  dimensions  of  an  average-sized  specimen. 

Formation  and  Locality. — Found  in  the  Corniferous  rocks  surrounding  the  Falls  of  the  Ohio,  in 
Kentucky  and  Indiana,  where  it  is,  however,  of  rare  occurrence.  As  far  as  my  information  goes,  only 
three  individuals  of  this  species  are  known.  This  species  has  some  resemblance  to  Hall's  Khyn.  indianensis 
of  the  Niagara  group,  but  it  is  easily  distinguished  from  that  species,  differing  from  it  by  its  larger  number 
of  plications  in  the  sinus  and  on  the  fold,  by  the  greater  extension  of  its  mesial  fold,  and  also  by  its 
greater  convexity  or  gibbosity. 


78  PALEONTOLOGY  OF  KENTUCKY. 

Rhynchonella  pisa.     HALL  AND  WHITFIKLD. 

Plate  XXXII.,  figures  24  to  27. 
Rhynchonella  pisa,  H.  and  W.     Pal.  of  Ohio,  Vol.  II.,  p.  135—1875. 

Shell  small,  globular  in  full-grown  specimens,  but  varying  from  depressed 
lenticular  to  highly  gibbous  at  different  stages  of  growth.  Gfeneral  outline  of 
the  shell  broadly  ovate,  widest  near  the  front  or  below  the  middle  of  the 
length.  Ventral  valve  less  gibbous  than  the  dorsal ;  beak  small,  pointed  and 
slightly  curved,  usually  projecting  but  moderately  beyond  that  of  the  opposite 
valve,  though  sometimes  rather  extended  ;  body  and  sides  of  the  valves  regu- 
larly rounded,  becoming  broadly  but  not  deeply  sinuate  in  front,  where  it  is 
prolonged  and  bent  upward  in  the  middle.  Dorsal  valve  regularly  convex, 
center  of  the  valve  most  prominent,  becoming  slightly  elevated  in  front,  form- 
ing a  not  very  prominent  mesial  elevation.  Surface  marked  by  from  twelve  to 
sixteen  rounded  plications,  which  are  distinctly  marked  on  sides  and  in  front, 
but  becoming  obsolete  soon  after  reaching  the  middle  of  the  valve  on  the  dorsal 
side,  but  are  continued  somewhat  further  on  the  ventral  valve,  and  in  some 
specimens  those  bordering  the  sinus  extend  to  near  the  beak.  On  the  dorsal 
valve  there  are  usually  four  plications  elevated  to  form  the  mesial  fold,  and 
three  depressed  in  the  ventral  sinus,  though  in  some  cases  there  are  only  three 
elevated  on  the  dorsal  valve.  This  species  resembles  Rhyn.  neglecta,  with 
which  it  is  associated,  but  differs  in  its  general  convexity  of  the  valves  and 
want  of  angularity  in  the  plications,  which  do  not  extend  to  the  beak  as  in 
that  species.  The  more  elongate  forms  have  some  similarity  to  Rhyn.  acinus, 
but  have  not  the  flattening  of  the  sides  and  surfaces  of  the  valves,  as  in  that 
species,  and  have,  moreover,  a  greater  number  of  plications.  The  more  ventri- 
cose  forms  resemble,  very  closely,  small  specimens  of  Rhyn.  nucleolata,  but, 
besides  being  more  elongate,  with  a  more  projecting  beak,  the  plications  are 
never  flattened  on  their  surfaces,  and  .are  destitute  of  the  groove  along  the 
middle,  as  in  that  one.  (Hall  and  Whitfield.) 

Formation  and  Locality. — Occurs  in  the  Niagara  rocks  of  the  quarries  east  of  the  city  of  Louis- 
ville. It  is  a  rather  rare  species.  The  specimen  illustrated  on  plate  u32  is  of  about  the  largest  size  this 
species  ever  attains. 

Rhynchonella  rugaecosta.    K.  sr. 

Plate  XXXII.,  figures  48,  49,  50  and  51. 

Shell  of  medium  size,  sub-triangular  or  sub-pentagonal ;  compressed  or  very 
moderately  convex  ;  width  to  length  as  three  to  two. 

Ventral  valve  moderately  convex  in  the  umbonal  region,  sloping  from  there 
in  a  straight  line  to  the  baso -lateral  margins,  but  rapidly,  almost  abruptly,  to 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  V9 

the  cardinal  borders ;  in  the  middle  part  of  the  valve  is  a  mesial  depression, 
which  extends  from  beak  to  base,  and  increases  in  depth  and  width  only  mod- 
erately towards  the  front ;  the  umbo  is  inflated,  and  the  beak  elevated,  pointed 
and  only  slightly  arched. 

Dorsal  valve  moderately  convex  only  at  the  umbo,  balance  only  slightly 
curved,  almost  flat ;  middle  of  valve  is  elevated  from  beak  to  front,  forming  a 
well  defined,  but  narrow  and  little  elevated  mesial  fold,  at  the  base  of  which 
the  front- margin  is  slightly  sinuate. 

The  surface  is  ornamented  by  simple  sub-angular  radiating  striae,  of  which 
four  to  five  on  each  side  of  the  mesial  fold  and  sinus  are  more  prominent,  and 
reach  from  the  baso-lateral  margins  back  to  the  beak  ;  they  are,  however,  only 
faintly  marked  in  the  umbonal  region  of  each  valve  ;  above  these  principal  ribs 
there  are  about  four  short  ones  on  each  side  of  the  mesial  fold  and  sinus,  ter- 
minating in  the  cardinal  margins,  the  uppermost  not  more  than  about  a  line 
from  the  dorsal  beak.  The  illustration  does  not  show  this  peculiar  feature, 
except  in  the  side-view,  where  it  is  faintly  indicated.  These  radii  are  crossed 
by  concentric  lamellose,  imbricating  striae,  which  become  crowded  towards  the 
front,  and  which  produce  the  rugose  appearance  of  the  shell.  The  specimen 
before  me  measures  six  lines  in  width,  four  in  length,  and  three  in  depth. 
There  are  no  plications  on  the  fold  nor  in  the  sinus.  This  species  is  easily 
distinguished  from  all  other  Rhynchonella. 

Formation  and  Locality. — Found  in  the  upper  strata  of  the  Niagara  group,  in  the  quarries  east  ot 
the  city  of  Louisville.  It  is  of  rare  occurrence. 

Rhynchonella  saffordi.    HALL. 

Plate  XXVII.,  figures  22.  23  and  24,  and  Plate  XXXIII.,  figures  4,  5  and  6. 
Rhynchonella  saffordi,  Hall.  Can.  Nat.  and  Geo.,  Vol.  V.,  .Niag.  group — 1860. 
Rhynchonella  saffordi,  Hall.  27th  Kep.  N.  Y.  State  Mus.,  pi.  9,  figs.  27-29—1875. 

Shell  somewhat  below  medium  size,  varying  from  ovate  to  spherical,  sub-pen- 
tagonal, having  the  five  sides  almost  equal,  the  front  or  base  generally  a  little 
larger  than  the  lateral  margins  and  the  slopes  of  the  beak ;  shell  very  gibbous. 
Ventral  valve  convex  or  depressed-convex,  greatest  convexity  a  little  below 
the  umbo,  from  where  it  curves  gently  towards  the  lateral  margins,  but  before 
reaching  these,  it  deflects  very  abruptly,  almost  forming  here  a  right-angle  ; 
beak  small  and  little  arched,  and  slightly  elevated  above  the  one  of  the  other 
valve ;  umbo  scarcely  noticeable.  In  the  upper  part  of  the  valve,  from  apex 
to  one-third  of  its  length,  there  is  a  slight  elevation  in  the  middle ;  from  the 
point  where  this  elevation  ceases,  some  of  the  central  plications  become  de- 
pressed, which  depression  is  only  very  slight  but  increases  towards  the  front ; 
here  the  depressed  part  of  the  valve  makes  a  sudden  and  abrupt,  almost  angu- 


80  PALEONTOLOGY    OF    KENTUCKY. 

lar  bend,  in  the  dorsal  direction.  The  number  of  depressed  plications  is  very 
variable,  running  from  three  to  nine ;  the  deflected  front  part  of  the  valve  is 
quadrilateral,  its  length  sometimes  exceeding  its  width  ;  its  deflection  amounts, 
usually,  to  ninety  degrees,  but  it  sometimes  exceeds  the  right-angle  a  few 
degrees. 

The  dorsal  valve  is  very  gibbous,  having  its  greatest  convexity  a  little  below 
the  middle  of  the  valve,  from  where  it  curves  regularly  and  gently  to  the  front 
and  rear,  but  very  abruptly  to  the  lateral  margins  ;  there  is  a  slight  depression 
in  the  middle  of  the  valve  from  apex  almost  half-way  down  or  even  a  little 
further.  Where  this  depression  terminates  some  of  the  central  plications, 
from  five  to  ten  in  number,  commence  to  rise,  increasing  in  elevation  towards 
the  front,  forming  here  a  kind  of  mesial  elevation.  This  valve  has  in  its  front 
part  a  quadrilateral  indentation,  corresponding  in  form  and  size  to  the  front 
extension  of  the  ventral  valve,  which  fits  into  it  exactly.  The  base  of  the 
shell  forms  a  regular  quadrangle.  The  surface  is  covered  by  fine  radiating 
plications,  rounded  or  somewhat  flattened,  some  of  which  bifurcate ;  they 
differ  in  size  and  number,  which  latter  runs  from  twenty  to  thirty.  Two  some- 
what different  forms  of  this  species  are  found,  as  represented  by  the  figures  in 
the  two  different  plates  ;  the  group  represented  on  plate  27  is  somewhat  longer 
than  wide,  and  its  plications  are  less  in  number,  and  markedly  coarser,  while 
the  shells  figured  on  plate  33,  are  wider  than  long,  with  finer  and  more  numer- 
ous plications;  but  there  are  so  many  specimens  of  intermediate  forms  con- 
necting the  two  groups,  that  I  feel  not  justified  to  separate  them  as  different 
species  or  varieties. 

This  species  differs  greatly  in  size  in  different  specimens  ;  one  of  average  size 
has  the  following  dimensions :  width,  seven  lines ;  length,  eight  lines,  and 
thickness,  from  six  to  seven  lines. 

Formation  and  Locality. — Occurs  somewhat  abundantly  in  the  Niagara  rocks  in  the  quarries  east 
of  the  city  of  Louisville,  Ky.,  where  even  well  preserved  specimens  are  not  rare.  This  species  was 
named  by  Prof.  Hall  after  Prof.  Safford,  of  Nashville,  Tennessee,  formerly  State  Geologist  of  Tennessee. 

Rhynchonella  saffordi  var.  depressa.    K.  VAR. 

.  Plate  XXXIII.,  figures  1,  2  and  3. 

Although  this  shell  agrees  in  so  many  points  with  Rhyn.  saffordi,  to  place  it 
with  that  species,  it,  on  the  other  hand,  possesses  some  very  important  features 
which  separate  it  from  saffordi,  and  which  I  think  justify  me  to  make  a  new 
variety  out  of  it.  These  features  are  as  follows : 

1.  This  shell  is  very  flat  or  compressed,  more  so  than  any  other  Rhyncho- 
nella of  its  size,  while  Rhyn.  saffordi  is  generally  very  ventricose. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  81 

2.  The  elevation  and  depression  of  the  central  plications  are  scarcely  notice- 
able in  this  shell. 

3.  The  beak  of  the  ventral  valve  is  more  pointed,  and  elevated  above  that  of 
the  other  valve.     One  of  my  specimens  of  this  species  shows  faint  traces  of 
very  fine  radiating  lines,  also  of  fine  concentric  striae  or  lines  of  growth  ;  both 
these  lines,  the  radiating  and  the  concentric,  may  also  be  found  in  more  per- 
fect specimens  of  Rhyn.  saffordi,  though  none  among  the  many  shells  of  that 
species  in  my  collection  show  them. 

Formation  and  Locality. — Associated  with  Rhyn.  saffordi  in  the  Niagara  rocks  in  the  quarries  east 
of  the  city  of  Louisville,  Ky.,  but  of  rare  occurrence. 

« 

Rhynchonella  Strickland!.    SOWKRBY. 

Plate  XXV1L,  figures  9,  10  and  11,  and  Plate  XXIX.,  figures  3  to  6. 
Terebratula  Stricklamli,,  Sowerby.     Sil.  Syst.,  pi.  13,  fig.  19—1839. 
Rhyn.  Tennesseensis  (Koemer),  Hall.     Trans.  Alb.  Inst.,  Vol.  IV. 
Rhyn.  Siricklandi,  Hall.     28th.  Kep.  N.  Y.  State  Museum— 1876. 
Rhyn.  Stricklandi,  Hall,     llth  Geol.  Kep.  of  Ind.,  p.  308,  pi.  26—1881. 

Shell  one  of  the  large-sized  Rhynchonellidae,  sub-ovate  or  sub-trigonal;  width 
sometimes  equal,  but  mostly  exceeding  the  length  ;  sides  and  front  rounded ; 
shell  almost  concavo-convex.  Surface  plicate. 

Ventral  valve  regularly  curved  from  beak  to  front  j  the  mesial  sinus,  which 
commences  below  the  umbo,  occupies,  from  that  point  to  the  front,  the  largest 
portion  of  the  valve ;  it  is  shallow  at  the  beginning,  but  deepens  approaching 
the  front.  On  each  side  of  the  sinus  are  five  plications  smaller  than  those 
occupying  the  mesial  depression ;  in  the  most  lateral  plication  the  margin  of 
the  valve  makes  a  very  abrupt  bend,  equalling .  or  exceeding  ninety  degrees 
towards  the  dorsal  valve,  forming  here  a  smooth,  vertical  border ;  beak  small 
and  incurved  over  the  umbo  of  the  other  valve.  The  sinus  contains  usually 
nine  strong,  simple  and  rounded  plications ;  the  whole  valve  has  from  eighteen 
to  twenty  of  these  ribs,  which  increase  in  size  and  distance  from  beak  to  front ; 
most  all  of  them  reach  to  the  front,  only  a  few  appear  to  be  somewhat  shorter. 
Dorsal  valve  is  very  gibbous  or  ventricose,  slightly  flattened  at  the  umbo ; 
mesial  fold  not  defined  on  the  umbo ;  from  there  it  becomes  gradually  more 
elevated  as  it  approaches  the  front,  where  it  is  more  or  less  prominent.  The 
fold  has  generally  four  plications  on  top  and  three  on  each  of  its  slopes  ; 
outside  of  the  mesial  elevation,  each  side  of  the  valve  contains  four  plications, 
thus  covering  the  whole  valve  with  about  eighteen  ribs  ;  those  on  the  fold  are 
somewhat  stronger  than  the  lateral.  In  the  last  lateral  plication  the  surface  of 
the  valve  bends  abruptly  towards  the  ventral  valve,  forming  here,  like  the  latter, 
a  smooth  border  of  considerable  size.  All  the  ribs  are  roundect  and  simple, 

OEOL.    SUR. — 11 


82  PALAEONTOLOGY    OF    KENTUCKY. 

and  increase  in  size  and  distance  from  beak  to  front.  The  ventral  valve  has 
its  mesial  depression  greatly  produced  in  front,  and  abruptly  turned  upwards, 
which  extension  fits  exactly  in  a  corresponding  indentation  in  the  base  of  the 
dorsal  valve.  There  are  no  radiating  striae  visible,  but  a  few  concentric  lines 
of  growth  may  be  noticed.  The  shells  of  this  species  were  originally  identified 
with  Rhyn.  tennesseensis,  a  species  described  by  Prof.  P.  Roemer,  of  Germany, 
from  the  Silurian  of  Tennessee,  and  they  are,  therefore,  generally  known 
under  that  name.  A  closer  examination  and  comparison  showed  the  former 
identification  as  erroneous,  and  placed  our  shells  in  their  present  species. 

Formation  and  Locality. — This  species  occurs  in  great  abundance  and  in  fine  and  well  preserved 
specimens  in  the  Niagara  rocks  at  Waldron  and  St.  Paul,  in  Indiana;  in  the  Niagara  strata  of  Kentucky, 
near  to  and  east  of  the  city  of  Louisville,  this  species  is  also  found,  but  very  rarely,  and  then  in  defective 
and  distorted  specimens.  The  best  individual,  so  far  as  I  know,  ever  found  in  our  quarries,  is  figured  on 
plate  27;  it  is  considerable  smaller  than  the  Waldron  shells,  but  has  their  exact  form  and  markings.  An- 
other specimen  which  I  found  associated  with  the  former,  has  the  same  shape  in  its  outlines,  but  shows  only 
faint  traces  of  the  plications  ;  its  surface  appears  almost  smooth. 

Rhynchonella  tenuistriata.    N- BP- 

Plate  XVII.,  figures  27,  28  and  29. 

Shell  rather  small,  sub-triangular  or  sub-pentagonal ;  cardinal  line  forms  a 
right-angle  at  the  beak;  its  two  sides,  which  are  somewhat  concave  or  in- 
curved, slope  down  below  the  middle  of  the  shell ;  here  they  meet  the  lateral 
margins,  with  which  they  form  again  an  almost  right-angle;  lateral  margins 
short,  about  one-third  the  length  of  the  shell,  almost  straight  or  very  slightly 
convex  ;  basal  margin  straight,  with  a  slight  concavity. 

Ventral  valve  less  convex  than  the  dorsal,  with  its  greatest  convexity  at  the 
umbo,  from  which  it  slopes  in  almost  straight  lines  to  the  lateral  margins ;  the 
cardinal  margins  deflect  abruptly  upwards  to  meet  the  margin  of  the  dorsal 
valve  in  one  and  the  same  plane  ;  below  the  umbo  the  central  portion  becomes 
depressed,  which  depression  increases  in  depth  and  width  towards  the  front, 
where  it  occupies  the  ralve  to  the  full  extent  of  the  basal  margin.  This  mesial 
sinus  is  rounded,  its  margins  are  not  well  defined,  and  its  depth  becomes  only 
somewhat  prominent  at  or  near  the  front ;  the  umbo  is  small,  the  beak  elevated 
above  that  of  the  other  valve,  and  very  little  arched.  The  dorsal  valve  very 
little  convex,  almost  flat  in  the  umbonal  region  and  below  it  to  the  basal  mar- 
gin, where  a  part  of  the  front  is  elevated  into  a  mesial  fold.  On  each  side  of 
this  mesial  fold  the  valve  slopes  down  very  abruptly  to  the  baso-lateral  mar- 
gins. The  mesial  fold  is  only  observeable  at  or  near  the  front ;  the  umbo  is 
inflated,  and  the  beak  small  and  incurved  into  the  opposite  valve.  The  surface 
of  both  valves  is  covered  by  slender,  sub-angular  or  rounded  radii,  of  which 
there  are  five  or  six  on  each  side  of  the  mesial  fold  and  sinus ;  the  fold  is 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  83 

occupied  by  about  seven,  while  the  sinus  only  contains  about  six.  These  striae 
increase  by  intercalation,  but  not  by  bifurcation.  Other  markings  of  the 
surface  are  not  observed. 

Formation  and  Locality. — Occurs  very  rarely  in  the  Corniferous  rock  of  the  Devonian  formation 
in  Kentucky  and  Indiana. 

Rhynchonella  tethys.    BILLINGS. 

Plate  XIII.,  figures  25  to  33,  and  Plate  XXXI.,  figures  22  to  25. 
Rhynchonella  tethys,  Billings.  Canadian  Journal,  p.  270 — 1860. 
Rhynchonella  tethys,  Hall.  Pal.  N.  Y.,  Vol.  IV.,  p.  335—1867. 

Shell  of  medium  size  among  ths  Rhynchonellidae,  sub- trigonal  ovate,  usually 
wider  than  long,  but  sometimes  length  and  width  equal.  Ventral  valve  de- 
pressed convex  in  the  upper  part,  nearly  flat  at  the  sides;  sinus,  beginning 
above  the  middle,  moderately  depressed  in  young  shells,  and  in  older  ones 
becoming  deep  in  front  and  abruptly  curving  towards  the  dorsal  valve.  Dorsal 
valve  moderately  convex  in  young  shells,  more  convex  and  finely  gibbous  in 
old  shells ;  the  broad  mesial  elevation  becoming  distinct  about  the  middle  of 
the  length.  Surface  marked  by  from  fifteen  to  eighteen  angular  plications, 
of  which  four  to  six  are  upon  the  mesial  fold,  and  three  to  five  in  the  median 
sinus,  while  about  five  or  six  cover  the  lateral  slopes  of  each  valve  on  each  side 
of  the  mesial  fold  or  sinus ;  plications  outside  of  fold  on  dorsal  valve  curve 
very  abruptly  outwards  as  well  as  downwards.  Fine  concentric  striae,  which 
are  undulated  in  crossing  the  plications,  mark  surface  of  shell,  but  this  feature 
is  rarely  preserved. 

Formation  and.  Locality. — Found  abundantly  and  in  well  preserved  specimens  in  the  Corniferous 
rock  at  and  around  the  Palls  of  the  Ohio,  however,  all  the  shells  found  are  in  a  silicified  condition,  by 
which,  generally,  the  finer  surface-markings  become  obliterated.  If  we  compare  the  shell  figured  on  plate 
31  with  those  on  plate  13,  it  appears  to  us  that  it  does  not  belong  to  the  same  species.  The  shell  on  plate 
31  has  its  plications  finer  and  rounded,  and  its  mesial  elevations  and  depressions  less  prominent;  it  has  six 
ribs  on  the  fold  and  five  in  the  sinus.  The  shells  on  plate  13  show  four  to  five  plications  on  the  fold,  and 
three  to  four  in  the  sinus;  all  the  ribs  are  coarse  and  angular.  But  if  we  compare  the  different  shells  in  a 
large  lot  of  from  fifty  to  sixty  individuals,  as  are  now  before  me,  it  is  impossible  to  draw  a  dividing  line; 
there  are  numerous  intermediates  connecting  the  two  extreme  forms,  which  must,  therefore,  be  classed  in 
one  and  the  same  species, 

Rhynchonella  increbescens.    HALL. 

Plate  XXXIV.,  figures  26-29. 
Atrypa  increbescens,  Hall.     Pal  N.  Y.,  Vol.  I.,  pi.  33,  p.  146—1843. 

Average  shell  small,  ovate-trigonal,  full-grown  specimens  quite  convex,  with 
slightly  greater  width  than  length.  Cardinal  slopes  nearly  straight  in  young 


84  PALEONTOLOGY    OF    KENTUCKY. 

examples,  slightly  curved  in  adult  specimens,  anterior  margins  rounded  to  the 
front. 

Dorsal  valve  greatly  convex,  particularly  towards  the  front,  approaching 
which  the  mesial  ridge  is  greatly  elevated  (especially  in  more  globose  speci- 
mens), and  is  gathered  into  four  plications.  The  sides  radiate  from  beak  in 
five  or  six  plications,  strongly  curved  towards  the  anterior  lateral  margins. 

Ventral  valve  is  depressed  from  beak  to  anterior  central  region,  where  it 
curves  more  strongly.  A  mesial  sinus  begins  at  beak,  has  sloping  sides,  three 
plications,  and  diverges  to  a  great  width  at  the  front,  where  it  terminates  in  an 
extended,  half -circular,  marginal  projection  corresponding  to,  elevation  in  the 
front  of  the  dorsal  valve.  The  sides  radiate  to  the  anterior  margins  in  five  or 
six  plications  rounding  towards  the  front. 

The  beak  of  the  ventral  valve  is  curved  so  as  to  hide  the  apex  of  the  dorsal 
valve.  The  angular  plications  and  furrows  give  the  margins  a  distinct  zigzag 
outline;  the  larger  specimens  show  several  lines  of  growth,  more  distinct 
towards  the  front,  crossing  the  plications  and  furrows. 

In  the  specimens  before  me  the  plications  in  the  lateral  slopes  vary  ;  some  are 
imperfectly  developed  and  almost  indistinct.  The  plications  in  the  mesial  sinus 
and  elevation  never  vary.  The  smaller  specimens  are  generally  more  com- 
pressed and  the  larger  more  rounded  in  outline  than  the  typical  forms. 

Formation  and  Locality. — This  shell  seems  to  be  confined  to  the  Upper  Trenton,  where  it  is  found 
quite  abundantly,  and  associated  with  Orthis  borealis.  It  occurs  in  most  of  the  blue-grass  counties  of  the 
State.  The  specimens  figured  are  from  Frankfort,  Ky. 


Genus  Rhynchotreta. 

Rhynchotreta,  Hall.    28th  Regent's  Report — 1879. 
Etymology :  rhynchos,  beak ;   tretos,  with  a  hole  in  it. 

Type :  Rhynchonella  cuneata,  Dalman. 

Shell  triangular ;  surface  with  angular  plications.  Ventral  beak  straight, 
produced  beyond  the  dorsal  beak,  extremely  perforated;  foramen  with  an 
elevated  margin  ;  space  between  the  foramen  and  hinge-line  occupied  by  a  del- 
tidium  in  two  pieces,  being  divided  by  a  longitudinal  suture,  and  transversely 
striated.  Valves  articulated  by  two  slender,  curving  teeth,  proceeding  from  a 
broad  curving  hinge-plate  in  the  ventral  valve,  which  fit  into  corresponding 
sockets  in  the  dorsal  valve.  Crurae  rising  from  near  the  dorsal  beak,  and  curv- 
ing into  the  ventral  cavity,  and  thence  recurved  towards  the  dorsal  side,  and 
probably  uniting.  Structure  fibrous,  and  apparently  yery  minutely  punctate. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  85 

Rhynchotreta  cuneata,  var.  americana.    HALL. 

[Plate  XXXII.,  figures  58,  59,  62  and  63. 

Rhynchotreta  cuneata,  var.  americana,  Hall.     28th  Rep.  N.  Y.  State  Museum,  Nat.  Hist.  Mus.,  p.  167 — 1879. 
Rhynchotreta  cuneata,  var.  americana,  Hall,     llth  Geol.  Rep.  of  Indiana,  p.  310,  pi.  25,  figs.  29-38 — 1881 

Shell  triangular,  cuneiform,  longer  than  wide,  greatest  width  near  the  froni 
and  tapering  posteriorly  into  an  angular  beak.  Valves  moderately  convex, 
the  dorsal  sometimes  gibbous,  ventral  beak  elongated,  foramen  sub- circular, 
formed  by  the  extremity  of  the  beak,  and  a  portion  of  the  area  below,  which 
is  separated  from  the  hinge- line  by  a  deltidium  in  two  pieces ;  sides  of  the 
beak  compressed,  flat  or  concave.  Sinus  wide,  deep  or  shallow,  according  to 
development  of  shell,  commencing  at  one-third  the  length  of  shell  from  beak, 
and  becoming  very  conspicuous  in  front. 

Dorsal  valve  the  more  convex,  the  mesial  fold  beginning  as  a  depression  just 
below  the  beak,  and  becoming  very  prominent  on  lower  half  of  shell.  Surface 
marked  by  nine  or  ten  strong  angular  plications  on  each  valve,  of  which  three 
are  depressed  in  the  sinus,  and  four  are  elevated  on  the  mesial  fold,  the  two 
central  ones  being  much  the  more  prominent;  the  plications  are  crossed  by 
numerous  regular  thread-like  striae.  The  entire  surface  is  minutely  papillose. 
(Hall.) 

Formation  and  Locality. — Found  in  the  Niagara  strata  east  of  the  city  of  Louisville,  Ky.  There 
it  is,  however,  extremely  rare,  and  the  few  specimens  found  are  not  well  preserved,  and  show,  besides,  that 
the  condition  of  our  Niagara  ocean  did  not  favor  their  development,  which  appears  to  have  been  poor. 
Numerous,  originally  well  developed,  and  afterwards  well  preserved  specimens  of  this  species  come  from 
Waldron,  Indiana.  In  that  locality  the  Niagara  sea  must  have  afforded  conditions  most  favorable  to  the 
development  of  its  rich  molluscan  fauna.  If  we  compare  this  species  with  its  European  congener,  we  find 
our  shell  more  robust  and  larger,  and  its  surface  is  marked  by  fewer  and  stronger  plications ;  while  the 
transverse  striae  are  a  little  finer  and  less  distant,  and  the  sinus  is  much  deeper  and  more  abrupt.  The 
figures  on  plate  32  are  copied  from  Hall's  28th  Report.  My  own  specimens  from  our  locality  were  not 
sufficiently  preserved  to  be  used  for  figures. 

Genus  Ambocoelia.    Haii. 

Shell  bivalve,  inequivalve,  equilateral,  plano-convex  or  concavo-convex ; 
valves  articulated  by  teeth  and  sockets ;  cardinal  line  equalling  the  greatest 
width  of  the  shell.  Area  common  to  both  valves  ;  foramen  triangular,  extend- 
ing also  to  the  area  of  the  dorsal  valve.  Dorsal  valve  flat,  depressed  convex  or 
concave  ;  cardinal  process  bifurcate.  The  foveal  plates  are  straight,  longitudi- 
nal, pointed  at  their  inner  extremities,  and  from  their  center  on  the  outside 
extends  a  callosity  curving  around  the  dental  sockets,  which  open  towards  the 
cardinal  line.  Muscular  impressions  four,  and  distinctly  marked  in  the  middle 
of  the  valve  or  below.  Ventral  valve  arcuate,  with  or  without  a  distinct  sinus  ; 


86  PALEONTOLOGY  OF  KENTUCKY. 

beak  arching  over  the  area ;  dental  lamellae  strong,  extending  in  short,  obtuse 
teeth.  The  impressions  of  the  cardinal  muscles  form  two  semi-oval  pits  near 
the  middle  of  the  concavity  between  the  beak  and  base  of  the  shell.  Surface 
very  finely  cancellated  by  obscure,  radiating  striae  and  fine  concentric  lines  of 
growth.  Shell-structure  fibrous  or  fibro-punctate ;  luster  pearly.  The  typical 
species  is  Ambocoelia  umbonata  of  Conrad. 

Ambocoelia  umbonata.    CONRAD. 

Plate  XVII.,  figures  26  and  26. 

Orthis  umbonata,  Conrad.     Jour.  Acad.  Nat.  Sci.,  Phil.,  Vol.  8. 
Orthis  umbonata  (Conrad),  Hall.     10th  Rep.  on  State  Cab.,  p.  167—1857. 
Ambocoelia  umbonata,  Hall.     13th  Kegent's  Rep.,  p.  71 — 1860. 
Orthis  nucleus,  Hall.     Geol.  Rep.  4th  disk,  pp.  180  and  181. 
Ambocoelia  nucleus,  Hall.     13th  Regent's  Rep.,  p.  71. 
Ambocoelia  umbonata,  Hall.     Pal.  N.  Y.,  Vol.  4,  p.  259—1867. 

Shell  very  small,  plano-convex,  sub-circular ;  length  and  width  in  our  speci- 
mens about  equal ;  hinge-line  equal  to  the  greatest  width  of  the  shell ;  cardinal 
extremities  either  obtuse-angular  or  rounded. 

Ventral  valve  gibbous,  with  the  umbo  extremely  elevated,  and  a  compara- 
tively large  incurved  beak ;  mesial  sinus  distinct,  extending  from  the  beak  to 
the  front;  it  is  shallow  and  rounded  at  the  bottom  ;  its  margins  are  also 
rounded  and  not  defined  ;  the  cardinal  area  is  rather  large  in  proportion  to  the 
small  size  of  the  shell ;  its  margins  are  sharply  defined ;  it  is  strongly  concave, 
and  has  a  large  triangular  fissure  in  its  center ;  the  beak  is  prominent  and 
strongly  incurved  into  the  upper  portion  of  the  foramen. 

Dorsal  valve  semi-elliptical,  depressed  convex  in  the  upper  central  portions, 
concave  below  the  middle  and  at  the  sides  ;  apex  scarcely  elevated  above  the 
hinge-line ;  area  very  narrow  and  almost  linear ;  there  is  no  indication  of  any 
kind  of  a  mesial  fold. 

Surface  marked  by  very  fine  radiating  and  concentric  striae,  the  latter  some- 
times becoming  crowded,  lamellose  and  imbricating  towards  the  front  of  the 
valves.  In  the  shells  of  our  rocks  these  surf  ace- markings  are  not  visible,  they 
became  obliterated  by  the  silicification  of  the  specimens. 

Formation  and  Locality. — Occurs  in  the  rotten  hornstone  of  the  Devonian  formation,  in  Jefferson 
county,  Ky.,  and  is  mainly  found  in  some  washes  east  of  the  city  of  Louisville,  where  it  occurs  in  great 
abundance,  but  of  considerably  smaller  size  than  eastern  specimens  of  the  same  species. 


87 


Genus  Athyris.    Mccoy. 

Athyris,  McCoy.     Carb.  foss.  Ireland — 1844. 
Etymology :  a,  without;  thuris,  a  small  door,  in  allusion  to  the  absence  of  a  deltidium  or  door. 

Shell  variable  in  shape  ;  valves  unequally  convex,  with  or  without  a  mesial 
sinus  and  fold ;  articulated  by  teeth  and  sockets.  Beak  of  ventral  valve  in- 
curved, usually  overlying  and  in  contact  with  beak  of  the  dorsal  valve,  and 
perforated  by  a  foramen,  or,  when  old,  the  foramen  fully  concealed.  In  the 
interior  of  ventral  valve  the  dental  plates  are  fixed  to  and  along  the  sides  of  a 
longitudinal  prominence  or  convex  arch- shaped  place,  which  extends  to  less 
than  a  third  of  the  length  of  the  shell,  with  its  narrow  end  fitting  into  the 
extremity  of  the  beak,  and  its  lateral  diverging  edges  to  bottom  of  valve.  The 
interior  of  the  dorsal  valve  is  partly  divided  by  a  large,  deep,  longitudinal 
septum,  which  extends  from  the  extremity  of  the  umbo  to  about  two-thirds  of 
the  length  of  the  shell,  supporting  at  its  origin  the  hinge-plate,  which  is 
divided  into  two  portions  by  a  narrow,  gradually  widening  channel.  To  the 
socket  ridges  are  affixed  the  spiral  cones,  the  extremities  of  which  are  directed 
towards  the  lateral  margins  of  the  shell ;  on  either  side  of  the  septum  are  seen 
two  muscular  scars  formed  by  the  adductor. 

Athyris  vittata.    HALL. 

Plate  XVI.,  figu-es  25-32. 

Athyris  vittata,  Hall.     Thirteenth  Eep.  on  State  Cab.,  p.  89—1860. 
Compare  Athyris  concentrica ;  A.  spiriferoides. 
Athyris  vittata,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  page  289,  plate  46—1867. 

Shell  sub-circular  or  sub- quadrate ;  gibbous ;  hinge-line  short,  with  cardinal 
extremities  rounded  ;  front  conspicuously  sinuate. 

Ventral  valve  gibbous  above,  more  convex  than  dorsal  valve ;  umbo  promi- 
nent ;  the  beak  incurved  and  truncated  in  the  plane  of  the  longitudinal  axis 
by  a  round  foramen ;  curving  very  abruptly  to  the  cardinal  and  lateral  mar- 
gins ;  the  center,  marked  by  a  mesial  sinus  which  extends  nearly  or  quite  to 
beak ;  it  is  shallow,  deepening  and  widening  towards  the  front ;  its  margins 
are  not  defined  but  rounded  and  coalesce  with  the  surface  of  the  valve ;  it  has 
a  considerable  basal  extension,  which  is  abruptly  bent  upwards  and  fits  into 
a  corresponding  indentation  of  the  other  valve.  Dorsal  valve  a  little  less  gib- 
bous than  the  ventral  one ;  sides  regularly  curving  from  the  umbo ;  about  the 
middle  of  the  valve  an  elevation  commences,  which  increases  towards  the  front, 
where  it  is  of  considerable  height,  thus  forming  a  conspicuous  mesial  fold ;  the 
beak  is  strongly  incurved  into  the  other  valve  below  its  beak, 


88  PALAEONTOLOGY    OF    KENTUCKY. 

Surface  marked  by  regularly  imbricating  lamellose  lines  of  growth,  which, 
on  the  surface  of  well  preserved  specimens  are  finely  crenulate  on  their  edges 
and  the  intermediate  spaces  striate.  In  most  of  the  specimens  found  the  sur- 
face is  entirely  smooth,  with  the  exception  of  a  small  strip  around  the  lateral 
and  basal  margins,  where  the  lines  of  growth  are  not  obliterated  by  the  silicifi- 
cation. 

Formation  and  Locality.—  Found  in  great  abundance  and  in  well  preserved  specimens  in  the  Cor- 
niferous  limestone  at  and  around  the  Palls  of  the  Ohio,  in  Kentucky  and  Indiana.  In  some  washes  of  the 
fields  around  Charlestown  the  ground  is,  after  some  hard  rains,  literally  covered  with  these  pretty  little 
shells.  This  species  bears  in  its  outlines  the  greatest  resemblance  to  Athyris  concentrica  of  Europe,  with 
which  it  is  undoubtedly  nearly  related,  but  it  may  be  easily  distinguished  from  that  species  by  not  having 
the  fine  concentric  lines  which  are  so  conspicuous  in  the  European  species.  From  Athyris  spiriferoides  it 
differs  partly  in  shape,  and,  according  to  Prof.  Hall's  statement,  mostly  in  internal  features.  Specimens 
are  found  showing  the  internal  spiral  coils  splendidly  preserved.  The  figures  25  and  31,  on  plate  16,  do 
not~show  plainly  enough  the  round  foramen  or  perforation  in  the  beak  of  the  ventral  valve, 

Genus  Atrypa.    Daiman. 

Atrypa,  Daiman.     Vet.  Acad  —  1827. 

Etymology:  a,  without;  trypa,  a  hole..    Daiman  supposed  that  this  shell  had  no  foramen  beneath  the  beak, 

which  it  has  ;  A  is,  therefore,  a  misnomer. 

Shell  inpunctate  and  fibrous  ;  surface  often  or  usually  ribbed,  and  often  fur- 
nished with  imbricating  lines  of  growth,  often  produced  into  foliaceous  ex- 
pansions ;  valves  articulated  by  teeth  and  sockets  ;  the  ventral  valve  often 
depressed  in  front,  with  or  without  a  mesial  sinus  ;  its  beak  incurved  and 
perforated  at  the  apex  by  a  minute  foramen,  which  is  sometimes  bounded  in 
front  by  a  deltidium.  Dorsal  valve  convex  and  often  very  ventricose,  with 
or  without  a  mesial  fold  ;  the  hinge-plate  divided  and  supporting  two  large 
conical  spires,  which  are  directed  into  the  hollow  of  the  dorsal  valve. 

Atrypa  aspera.      SCHLOTHEIM. 


Plate  XI  V.,  figures  1  to  11. 
List  of  synonyms,  see  Hall's  Pal.  of  New  York,  volume  4,  page  322. 

Shell  of  medium  size  ;  sub-circular  or  oval,  moderately  convex  ;  length  and 
width  almost  equal  ;  hinge-line  shorter  than  width  of  shell  ;  cardinal  extremi- 
ties rounded  ;  lateral  margins  gently  curved  ;  basal  margin  somewhat  more 
arcuate  in  some  specimens,  while  in  others  the  curvature  is  less.  The  central 
part  of  the  base  is,  in  some  shells,  slightly  extended,  while  in  others  this  fea- 
ture does  not  exist.  Ventral  valve  depressed  convex,  gently  and  regularly 
curving  from  beak  to  base  ;  lateral  margins  slightly  elevated  over  adjacent 
portion  of  valve  ;  beak  moderate  and  incurved  over  umbo  of  opposite  valve. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  89 

Mesial  depression  broad  but  very  shallow,  and  not  extending  back  beyond  the 
basal  third  of  the  valve  :  in  some  instances  no  depression  is  observable.  Dor- 
sal valve  more  or  less  convex,  according  to  age;  in  young  shells  nearly  flat,  in 
old  ones,  on  the  contrary,  even  gibbous.  Mesial  fold  only  faintly  indicated  in 
very  old  specimens;  in  all  others  not  the  slightest  trace  of  it  is  visible.  Surface 
marked  by  strong  angular  plications,  which  increase  towards  the  margins  by 
bifurcation,  and  by  lamellose,  imbricating  concentric  striae,  which  give  the 
shell  a  rugose  appearance. 

This  species  is  easily  distinguished  from  its  congener,  Atrypa  reticularis,  by 
its  stronger  radii,  and  by  its  rugose  surface  ;  also  by  its  smaller  size ;  its  largest 
specimens  seldom  exceed  in  length  and  width  one-half  of  cardinal  dimensions 
of  the  larger  A.  reticularis. 

Formation  and  Locality. — Found  in  the  upper  strata  of  the  Devonian  limestone,  in  Jefferson  county, 
Ky.,  and  in  Clark  county,  Indiana.  The  steep  banks  on  the  Indiana  side  of  the  Ohio  river,  opposite  the 
Falls,  have  furnished  a  considerable  number  of  very  fine  specimens  of  this  species.  It  is  a  peculiar  ap- 
pearance, that  in  the  rotten  hornstone  of  those  banks,  the  ventral  valves  of  this  species  occur  very  abund- 
antly, weathered  out  and  silicified,  while  very  seldom  a  single  dorsal  valve. is  found.  I  have,  for  instance, 
collected  there  more  than  twenty-five  single  ventral  valves,  but  did  not  find  a  single  dorsal  one.  In  some 
of  the  specimens  there  found,  both  valves  are  perfect  and  at  the  same  time  separate,  showing  exquisitely 
the  interior  arrangement  of  the  shell. 

Atrypa  calvini.    x.  SP. 

Plate  XXXII.,  figures  64,  65  and  66. 

Shell  below  medium  size  ;  sub-circular  or  sub-elliptical ;  moderately  convex  ; 
hinge-line  less  than  greatest  width  of  shell ;  cardinal  extremities  rounded  or 
forming  a  very  obtuse  angle ;  width  greater  than  length.  Surface  plicated. 

Ventral  valve  depressed  convex  ;  greatest  convexity  below  the  umbo,  from 
where  it  slopes  very  gently  toward  the  cardino-lateral  margins ;  both  margins 
of  the  valve,  from  the  cardinal  extremities  down  to  the  front  of  the  mesial 
extension,  are  abruptly  and  prominently  turned  downward,  forming  a  flange 
of  considerable  size  in  proportion  to  the  shell,  and  establishing  on  the  valve 
two  lateral  depressions,  which  are  separated  from  the  sinus  by  its  elevated  mar- 
gins ;  the  sinus  begins  at  the  beak,  is  well  defined,  curves  regularly  and  gently 
towards  the  front,  where  it  deflects  abruptly  upward,  and  forms  a  large  quad- 
rilateral extension,  which  fits  in  a  corresponding  indentation  in  the  base  of  the 
dorsal  valve  ;  beak  prominent  and  elevated  above  the  beak  of  the  other  valve; 
only  slightly  arched,  and  having  a  small,  round  perforation  in  the  apex.  Dor- 
sal valve  more  convex,  almost  gibbous  ;  greatest  convexity  at  the  middle  of  the 
valve,  from  where  it  slopes  abruptly  to  the  lateral  basal  margins  ;  the  mesial 
fold  is  well  defined  from  beak  to  base,  becoming  prominent  at  the  front ;  beak 
very  small  and  incurved  into  the  fissure  of  the  opposite  valve  ;  umbo  almost 
Depressed. 

OKOL.    SUR. — 12 


90  PALAEONTOLOGY    OF    KENTUCKY. 

Surface  is  marked  by  strong,  rounded  plications.  The  sinus  is  bounded  by 
a  strong  rib  on  each  side ;  this  rib  bifurcates  below  the  umbo,  and  the  branch 
next  to  the  sinus  drops  into  it,  and  at  the  front  coalesces  with  the  elevated 
flange  of  its  extension ;  another  rib  starts  in  the  bottom  of  the  sinus  in  front  of 
the  umbo,  and  extends  to  the  termination  of  the  sinus,  having  sometimes 
bifurcated  at  about  the  middle  of  its  length.  The  mesial  fold  has  generally 
two  plications  on  its  summit  and  one  on  each  of  its  lateral  slopes,  but  the  top 
ribs  are  often  increased  by  bifurcation  before  they  reach  the  front.  On  each 
side  of  the  mesial  fold  and  sinus  there  are  about  five  or*  six  plications,  of 
which  only  two  reach  the  apex;  the  others  were  added,  partly  by  bifurcation, 
partly  by  interpolation.  Other  surf  ace- markings  are  not  visible. 

Formation  and  Locality. — Found  in  the  Niagara  group  in  the  quarries  east  of  the  city  of  Louis- 
ville, Ky.  Although  rare,  some  very  fine  specimens  may  be  seen  in  some  of  the  Louisville  collections. 
This  species  has  in  its  general  outline  some  resemblance  to  Khynchonella  whitii,  of  the  Niagara  rocks  from 
Waldron,  Indiana,  but  it  differs  from  it  by  its  peculiar  plications,  and  by  the  marginal  flange  of  its  ventral 
valve,  which  two  features  are  sufficient  to  distinguish  it  at  the  first  glance  from  that  species.  A  still 
greater  resemblance  has  it  to  Atrypa  nodostriata,  as  figured  by  Prof.  Hall  in  Pal.  of  Ohio,  Vol.  2,  plate  7, 
figures  12,  13  and  14,  and  described  in  same  volume,  page  133.  Differences  between  these  figures  and  our 
shells  exist  only  in  one  or  two  minor  points,  which  are  easily  accounted  for  by  the  fact  that  the  Ohioan  illus- 
trations were  made  from  an  exfoliated  cast,  while  my  specimens  are  perfect  shells.  In  consequence  of  this 
great  resemblance,  which  amounts  almost  to  indentity,  I  placed  my  shells,  at  first,  in  the  species  of  A. 
nodostriata.  But  when  I  examined  Prof.  Hall's  original  description  and  figures  of  that  species,  in  Pal.  N. 
Y.,  Vol.  2,  page  272,  and  plate  56,  figures  2a-n,  I  could  not  identify  my  specimens  by  either.  It  appears  to 
me  that  the  description  and  illustrations  in  the  New  York  Keport  are  entirely  different  from  those  of  the 
Ohio  Keport.  By  the  New  York  description  and  figures  the  species  is  established.  The  Ohio  shell,  which 
is  only  an  exfoliated  cast,  belongs,  undoubtedly,  to  one  and  the  same  species  with  my  specimens,  but  not  to 
Atrypa  nodostriata  of  the  New  York  Report.  For  these  reasons  I  have  to  establish  a  new  species  for  the 
reception  of  my  specimens  and  the  cast  figured  in  the  Ohio  Report,  and  I  name  this  species  in  honor  of 
Prof.  Samuel  Calvin,  of  Iowa  City,  Iowa,  who  ranks  as  scientist  with  the  foremost  of  this  country,  and 
whose  labors  in  Geology  and  Palaeontology  have  greatly  contributed  to  the  wonderful  progress  made  by 
those  sciences  in  the  latter  half  of  the  present  century. 

Atrypa  ellipsoida.    N.  SP. 

Of  this  beautiful  shell  I  have  two  specimens  in  my  collection,  and  if  I  am 
not  mistaken,  I  have  seen  one  or  two  in  some  other  cabinets.  It  took  me  some 
time  before  I  could  come  to  a  conclusion,  whether  to  leave  it  with  Atrypa 
reticularis,  which  it  resembles  in  every  feature,  except  the  form,  or  to  place 
it  into  a  new  species.  I  have  decided  to  take  the  latter  course,  and  I  hope 
future  developments  in  regard  to  this  shell  will  prove  my  decision  to  be  cor- 
rect. The  description  of  this  new  species  is  as  follows : 

Shell,  'in  proportion  to  the  common  size  of  our  A.  reticularis,  rather  small ; 
longitudinally  sub-elliptical,  the  shell  forming  almost  a  regular  ellipsoid ; 
length  about  one  and  one-half  its  width,  while  its  depth,  measured  at  the 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  91 

points  of  greatest  convexity,  equals  the  width ;  hinge-line  short  and  sloping 
from  the  beaks  with  a  forward  deflection  to  the  cardinal  extremities,  which  are 
rounded ;  lateral  margins  slightly  curved  or  almost  straight ;  basal  margin 
strongly  curved  and  sometimes  even  forming  a  pointed  basal  extremity.  Sur- 
face covered  with  plications. 

Ventral  valve  less  convex  than  the  other ;  greatest  convexity  at  the  umbo, 
from  which  it  slopes  in  a  gentle  curve  to  the  front,  and  to  the  basal  half  of 
the  lateral  margins,  but  more  rapidly,  almost  abruptly,  to  the  cardi no-lateral 
margins.  The  umbo  is  prominent,  and  the  beak  somewhat  elevated  above, 
but  incurving  closely  upon  the  umbo  of  opposite  valve.  No  hinge-area  nor  a 
perforation  in  the  beak  are  visible.  The  dorsal  valve  is  more  gibbous,  it  slopes 
in  a  regular,  light  curve  to  the  base,  but  in  a  considerably  stronger  curve  to  the 
lateral  and  cardinal  lines ;  its  umbo  is  prominent,  and  its  beak  is  closely  in- 
curved into  the  opposite  valve.  It  is  only  near,  almost  at  the  base,  where  the 
dorsal  valve  shows  a  faint  elevation,  indicating  a  mesial  fold,  and  the  ventral 
valve  a  slight  impression  in  place  of  a  mesial  sinus.  The  dimensions  of  an 
average-sized  specimen  are :  length,  nine-tenths  of  an  inch ;  width  and  depth, 
six-tenths  of  an  inch. 

Formation  and  Locality. — In  the  Corniferous   limestone  at  the  Falls  of  the  Ohio,  on  the  Indiana 
shore  of  the  river. 

Atrypa  reticularis.    LINNAEUS. 

Plate  XIV.,  figures  12  to  23,  and  Plate  XV.,  figure  1. 
Atrypa  reticularis,  Linnaeus.     Syst.  Nat.  ed.  XII.,  p.  1132 — 1767. 
Atrypa  reticularis,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  316—1867. 
See  list  of  synonyms  in  last  cited  report. 

Shell  large,  sub-circular  or  ovoid,  convex-concave,  but  mostly  plano-convex ; 
length  and  width  almost  equal,  sometimes  width  a  little  greater  than  length; 
surface  plicated;  hinge-line  less  than  width  of  shell ;  cardinal  extremities 
rounded,  lateral  margins  gently  and  regularly  curved  ;  basal  margin  forming  a 
somewhat  stronger  curve,  which  is  sometimes  interrupted  by  a  small  extension 
of  the  mesial  sinus,  but  oftener  by  a  slight  inflection,  caused  also  by  sinus. 
Dorsal  valve  very  ventricose,  sometimes  gibbous,  having  greatest  convexity 
either  at  the  umbo  or  in  front  of  it,  from  where  it  slopes  abruptly  to  the  cardi- 
nal and  lateral  margins,  but  more  gently  to  the  front.  In  some  shells  there  is 
a  slight  elevation  in  the  center  line  of  the  valve  from  beak  to  base,  indicating 
a  kind  of  mesial  fold,  but  in  most  specimens  this  feature  does  not  exist ;  the 
umbo  is  prominent  and  regularly  rounded ;  beak  strongly  incurved  into  the 
fissure  of  the  other  valve.  Ventral  valve  depressed  convex  in  the  upper  part 
near  the  umbo,  but  becoming  concave  on  the  sides  and  in  front  of  it.  A  broad 


02  PALAEONTOLOGY    OF    KENTUCKY. 

shallow  depression  on  both  sides  of  the  umbonal  region  extends  from  the  car- 
dinal line  towards  the  front,  where  it  connects  with  the  mesial  sinus  ;  the  sinus 
begins  at  the  middle  of  the  valve  and  forms  a  slight  extension  in  front. 

In  a  few  instances  this  extension  bends  abruptly  upwards,  and  fits  in  a  cor- 
responding inflection  in  the  dorsal  valve  ;  beak  moderate  and  closely  incurved 
upon  the  umbo  of  the  other  valve,  showing  a  slight,  rounded  perforation  in 
the  apex,  which  leads  into  the  broad  triangular  fissure  ;  cardinal  area  scarcely 
visible.  Surface  ornamented  by  strong,  rounded  or  sub-angular  plications, 
which  increase  towards  the  margins  by  bifurcation  as  well  as  by  interpolation, 
and  by  lamellose,  imbricating  concentric  striae  or  lines  of  growth,  which  often 
give  the  shell  a  very  rugose  appearance,  as  may  be  seen  in  figure  1,  plate  15. 
The  size  of  the  specimens  in  this  species  differs  greatly  among  the  individuals 
illustrated;  the  larger  may  be  considered  as  of  maximum  size,  while  the 
smaller  are  of  average  size. 

Formation  and  Locality. — This  species,  together  with  Spirifera  oweni,  with  which  it  is  associated, 
belong  to  the  most  common  fossils  of  the  Corniferous  limestone,  at  and  around  the  Falls  of  the  Ohio  in 
Kentucky  and  Indiana.  In  the  washes  of  the  fields  around  Charlestown,  Indiana,  a  collector  can  pick  up, 
after  some  hard  rains,  in  a  day's  hunt,  more  than  a  hundred  fair  specimens  of  this  species ;  they  are  mostly 
silicified,  and  often  contain  the  spiral  coils,  as  may  be  seen  in  figures  18,  20,  21  and  22.  There  is  a  pretty 
little  shell  in  the  Niagara  rocks,  which  is  placed  also  in  this  species,  though  the  difference  in  the  exterior 
features  of  the  Devonian  and  Silurian  shells  is  so  conspicuous,  that  nobody  can  overlook  it.  For  what 
reason  these  two  fossils  are  kept  in  the  same  species  I  can  not  understand,  and  I  shall,  therefore,  separate 
the  Niagara  specimens  from  the  Devonian,  at  least  as  a  variety. 

Atrypa  reticularis,  var,  niagarensis,    N.  TAB. 

Plate  XXXII.,  figures  5  to  8,  and  44  to  47. 

Shell  small,  at  least  below  medium  size  ;  longitudinally  sub-elliptical  or  sub- 
ovate,  plano-convex ;  hinge-line  less  than  the  width  of  the  shell  ;  cardinal 
extremities  rounded ;  length  somewhat  greater  than  the  width  ;  base  regularly 
curved,  sometimes  slightly  inflected  in  the  center ;  lateral  margins  gently 
curved. 

Ventral  valve  slightly  convex  in  the  umbonal  region  ;  all  around  this  and  to 
the  base  there  exists  a  slight  depression,  which  forms  at  the  front  the  mesial 
sinus;  beak  moderate  and  incurved  upon  the  umbo  of  the  other  valve.  In 
some  specimens  the  sinus  is  produced  beyond  the  front,  and  the  extension, 
thus  formed,  often  rapidly  and  abruptly  bends  upward,  as  may  be  seen  in  figure 
7,  plate  32 ;  in  others  there  is  scarcely  a  sinus  noticeable.  Dorsal  valve  very 
ventricose  or  gibbous,  sloping  abruptly  from  the  middle,  where  the  greatest 
convexity  is,  toward  the  cardinal  and  lateral  margins,  but  less  abruptly  towards 
the  front.  No  mesial  elevation  is  indicated,  except  in  those  specimens  where 
the  frontal  extension  of  the  ventral  valve  makes  an  abrupt  upward  turn  ;  here 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  93 

the  dorsal  valve  is  also  deflected  upward  at  the  base  and  in  the  basal  quarter. 
Surface  covered  by  fine  thread-like  striae,  which  increase  towards  the  margins 
by  bifurcation ;  there  are,  also,  tine  concentric  lines  of  growth. 

Formation  and  Locality. — Found  abundantly  and  as  well  preserved  specimens  in  the  Niagara  rocks 
in  Jefferson  county,  Ky.,  and  in  Clark  county,  Indiana.  It  differs  from  its  Devonian  cousin  by  its  consid- 
erably smaller  size,  which  seldom  exceeds  that  of  the  specimens  illustrated  on  plate  32,  and  also  by  the 
finer  and  elegant  ornamentation  u[  its  suri'uco, 

Genus  Cyrtia.    Daiman. 

Cyrtia,  Daiman.     Kongl.  Vet.  Acad.  Handl.— 1827. 
Etymology :  Kyrtia,  a  fishing  basket. 

This  genus  includes  certain  spiriferoid  forms,  possessing  semi- conical  or 
semi-pyramidal  ventral  valves,  high,  flat  areas,  with  a  narrow  fissure  closed  by 
a  convex  pseudo-deltidium.  Some  of  the  species  have  a  round  perforation  in 
the  upper  part  of  the  pseudo-deltidium ;  but  this  feature  is  not  constant;  it 
may  be  present  or  absent,  and  has  not  been  considered  of  generic  significance. 
The  types  of  Daiman' s  genus,  Cyrtia,  are  C.  exporrecta  and  C.  trapezoidalis, 
which  are  now  considered  identical.  In  1858,  Mr.  Davidson  separated  several 
species,  which  were  then  classed  with  Cyrtia,  from  it,  because  they  did  not 
correspond  with  the  types  in  several  important  points,  and  placed  these  in  the 
genus  Cyrtina.  Both  genera  differ  in  the  shell  structure,  which  in  Cyrtia  is 
impunctate,  while  it  is  punctate  in  Cyrtina.  The  dental  plates  of  the  ventral 
valve  in  Cyrtia  are  similar  to  those  of  Spirifera,  while  those  in  the  ventral 
valve  of  Cyrtiua  are  greatly  different  and  show  a  peculiar  modification. 

Cyrtia  exporrecta.     WAHLKNBBRQ. 

Plate  XXVII.,  figures  6,  7,  8  and  20. 

Cyrtia  exporrecta,  Wahlenberg.     Nova.  Acta.  Regiae.  Soc.  Sci.,  Vol.  8,  Niagara  group — 1821. 
Spirifera  (Cyrtia)  trapezoides.     Hall.    24th  Rep.  N.  Y.  State  Museum,  p.  183—1872. 
Oyrtia  trapezoides,  Hall.    27th  Rep.  N.  Y.  State  Museum,  pi.  9,  figures  19,  20  and  21—1875. 

Shell  below  medium  size,  pyramidal  when  resting  on  the  dorsal  valve  ;  hinge 
line  longer  than  the  greatest  width  of  the  shell,  but  sometimes  a  little  less. 
Cardinal  extremities  mostly  acute,  sometimes  obtuse,  but  never  rounded.  Sur- 
face smooth  without  plications.  Ventral  valve  regularly  pyramidal,  forming 
at  the  apex  an  almost  right-angle  triangle.  Mesial  sinus  extending  from  apex 
to  front,  where  it  forms  a  medium  sized  quadrilateral  extension,  well  defined, 
but  shallow  and  rounded  or  flattened  in  the  bottom,  and  rather  narrow  in 
front.  Cardinal  area  greatly  elevated,  sharply  defined  in  its  margins,  more  or 
less  concave,  being  mostly  vertical,  but  sometimes  leaning  a  little  either  to  the 


94  PALAEONTOLOGY    OF    KENTUCKY. 

front  or  rear.  Beak  arching  over  a  high  but  very  narrow  fissure,  which  is  gen- 
erally closed,  and  shows  a  foramen  a  little  above  the  middle,  as  may  be  seen 
in  figure  35,  plate  34. 

Dorsal  valve  semi-elliptical,  depressed  ventricose ;  greatest  convexity  about 
the  middle,  from  where  it  slopes  with  a  gentle  curve  to  the  front  and  sides, 
but  flattened  at  the  cardinal  angles ;  mesial  fold  well  defined,  extending  from 
beak  to  front,  low  and  flattened,  or  even  depressed  in  the  middle ;  beak  in- 
curved over  a  very  narrow  or  linear  area. 

Surface  marked  by  fine  radiating  striae,  which  increase  in  size  and  distance 
from  apex  to  front ;  there  is  neither  bifurcation  nor  interpolation  of  striae. 

Size  of  this  species  is  somewhat  variable  ;  a  specimen  of  average  size  has  the 
following  dimensions :  length,  six  lines ;  height,  seven  lines,  and  width,  nine 
lines  and  one-half.  In  figure  6,  plate  27,  the  dorsal  valve  is  represented  with 
rounded  cardinal  angles,  which  is  a  mistake,  caused  by  defects  in  the  specimen 
copied.  The  angles  should  be  obtuse. 

Formation  and  Locality. — Occurs  in  the  upper  strata  of  the  Niagara  formation,  in  the  quarries  east 
of  the  city  of  Louisville,  Ky.     It  is  not  very  rare,  though  well  preserved  specimens  are  seldom  found. 

Cyrtia  exporrecta,  var.  arrecta.    HALL. 

Plate  XXVII.,  figure  21,  and  plate  XXXIV.,  figure  35;  plate  XXXII.,  figures  60  and  61. 
Spirifera  (Cyrtia)  exporrecta,  var.  arrecta,  Hall.    24th  Kep.  N.  Y.  State  Museum,  page  183 — 1872. 
Cyrtia  trapezoidalis,  var.  arrecta,  Hall.     27th  Rep.  N.  Y.  Museum,  pi.  9,  figures  22  and  23 — 1875. 

This  shell  resembles  in  most  important  points  the  preceding  species,  from 
which  it,  however,  differs  in  the  following  features  ; 

1.  The  cardinal  area  of  its  ventral  valve  is  more  elevated,  narrower  in  its 
base,  and  never  curved,  but   always  straight,  and  generally  leaning  a  little 
towards  the  front.     In  several  specimens  before  me,  the  cardinal  area  shows, 
even  in  its  upper  part,  a  marked  convexity,  the  beak  curving  really  a  little 
into  the  mesial  sinus ;  but  this  feature  may  be  the   consequence  of  distortion, 
though  the  shells  in  question  do  not  show  any  indications  of  being  subjected 
to  any  compression  or  other  violence. 

2.  The  excess  of  its  height  over  its  length  is  in  these  specimens  considerably 
greater  than  in  the  foregoing  species. 

3.  Its  mesial  sinus  appears  to  be  somewhat  more  angular,  and  proportionably 
deeper  than  that  of  Cyrtia  exporrecta. 

It  is  obvious  that  specimens  exist  which  may,  with  equal  right,  be  placed  in 
either  species,  but  usually  the  species  are  easily  separated. 

Formation  and  Locality. — Found  associated  with  the  former  in  the  upper  strata  of  the  Niagara 
formation,  in  the  quarries  east  of  the  city  of  Louisville,  Ky.  Is  rather  rare. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  95 

Genus  Cyrtina.    Davidson. 

Cyrtina,  Davidson.     Monog.  Brit.  Carb.  Brachiopoda — 1858. 
Etymology:  Kyrtia,  a  fishing  basket. 

Shell  small  and  resembling  that  of  Spirifera  in  its  general  form.  Shell  struc- 
ture punctate.  Valves  very  unequal ;  ventral  valve  elevated  and  pyramidal 
in  shape  ;  area  very  high,  with  a  long  narrow  foramen,  closed  by  a  pseudo-del- 
tidium ;  dental  lamellae  converging  from  margins  of  foramen,  and  uniting  to 
form  a  mesial  plate  or  septum,  which  divides  the  cavity  of  the  ventral  valve 
into  two  compartments.  Dorsal  valve  nearly  flat  or  moderately  convex. 
Spires  well  developed,  and  resembling  those  of  Spirifera  and  Spiriferina. 
The  genus  Cyrtina  is  closely  allied  to  Cyrtia,  of  Dalman,  and  Spiriferina,  of 
D'Orbigny,  and  has,  also,  near  relationship  with  the  genus  Spirifera. 

Cyrtina  crassa.    HALL. 

Plate  XIII.,  figures  21,  22,  23  and  24. 
Cyrtina  crassa,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  267,  pi.  27—1867 

Shell  depressed  pyramidal,  semi- elliptical  in  a  dorsal  view  ;  hinge-line  about 
equal  to  greatest  width  of  shell,  with  the  extremities  slightly  rounded ;  surface 
plicate  ;  shell  of  medium  size. 

Ventral  valve  depressed  pyramidal,  convex  regularly  arched  from  beak  to 
front,  and  also  from  sinus  to  margins  of  cardinal  area ;  sinus  broad  and 
rounded  in  botiom  ;  beak  extended  and  slightly  incurved  over  area,  which  has 
a  height  equal  to  one-half  the  width  of  shell,  and  which  is  almost  straight  in 
its  lower  half,  and  regularly  curved  in  the  upper  part ;  fissure  prominent,  twice 
as  high  as  wide  in  the  base1. 

Dorsal  valve  slightly  convex,  little  curved  from  front  to  rear  or  in  lat- 
eral direction ;  flat  or  even  a  little  concave  at  cardinal-extremities ;  mesial  fold 
broad,  moderately  elevated,  rounded  on  top  and  strongly  defined ;  cardinal 
area  linear. 

Surface  marked  on  each  side  of  the  mesial  fold  and  sinus  by  about  four 
strong,  low,  rounded  plications,  which  are  crossed  by  fine,  thread-like  con- 
centric striae,  and  a  few  imbricating  folds.  (Hall.)  Size  of  the  only  specimen 
in  my  possession  is  as  follows :  length,  nine  lines ;  width,  fourteen  and  one- 
half  lines  ;  and  depth,  nine  lines  and  one-half. 

Formation  and  Locality. — Occurs  in  the  Corniferous  limestone  around  the  Falls  of  the  Ohio,  but 
is  exceedingly  rare.  So  far  as  I  know,  only  three  specimens  of  this  species  were  ever  found ;  two  of  them 
belonged  to  the  cabinet  of  the  late  Dr.  James  Knapp,  and  the  third  one  was  found  by  myself}  it  is  copied 
on  plate  13, 


96  PALAEONTOLOGY    OF    KENTUCKY. 

Cyrtina  hamiltoniae.    HALL. 

Plate  XIII.,  figures  4  to  12. 

Cyrtia  hamiltonensis,  Hall.     Tenth  Kep.  on  St.  Cab.,  p.  166—1857. 
Cyrtia  hamiltonensis,  Billings.     Dev.  Foss.  of  Can.  "West.,  p.  263 — 1861. 
Compare  Cyrtia  acutirostra,  Shumard,  Geol.  Kep.  Missouri,  part  1,  p.  204 — 1854. 
Cyrtina  hamiltonensis,  Nicholson.     Pal.  of  Ontario,  p.  83 — 1874. 
Cyrtina  hamiltoniae,  Hall.    24th  Rep.  N.  Y.  St.  Mus.,  p.  198—1872. 

Shell  small,  more  or  less  triangular,  sub-pyramidal ;  hinge-line  equal  to 
greatest  width  of  shell ;  proportions  of  length,  width  and  depth  variable,  but 
frequently  width  is  equal  to  length  of  ventral  valve,  and  height  of  area  is  equal 
to  length  of  dorsal  valve.  Surface  plicate. 

Ventral  valve  quadrilateral  in  outline,  obliquely  sub-pyramidal,  most  promi- 
nent at  beak,  which  is  very  variable  in  elevation,  and  straight  or  a  little  arched 
over  cardinal  area,  and  not  unfrequently  attenuate  and  distorted  or  turned  to 
one  side ;  mesial  sinus  wide  and  strongly  defined,  rounded  or  sub-angular  in 
bottom  ;  area  variable,  large  and  elevated,  plane  or  arcuate  in  different  degrees, 
with  its  lateral  margins  angular,  distinctly  striate  in  both  directions ;  fissure 
narrow,  closed  by  a  convex,  pseudo-deltidium,  which  is  perforated  above  by 
an  oval  foramen.  Dorsal  valve  depressed  convex,  with  a  broad,  more  or  less 
prominent  mesial  fold,  which  is  bounded  by  broader  furrows  than  those  be- 
tween the  plications,  and  is  sometimes  extremely  elevated  in  front ;  beak 
scarcely  rising  above  hinge-line  ;  area  narrow,  almost  linear,  but  quite  distinct. 

Surface  marked  by  about  six  to  eight  (rarely  one  or  two  more)  simple, 
rounded  plications  on  each  side  of  mesial  fold  or  sinus,  and  these  are  crossed 
by  very  fine  concentric  lines  of  growth,  which,  at  intervals,  become  crowded 
and  sub -imbricate,  especially  towards  margins  of  shell.  The  finer  surface- 
marking  is  minutely  granulose  or  papillose  and  shell  structure  distinctly  punc- 
tate. In  some  of  the  larger  individuals  there  is  an  obscure  elevation  on  each 
slope  of  sinus,  resembling  an  obsolete  plication.  The  longitudinal  medium 
septum  extends  for  more  than  half  the  length  of  the  ventral  valve,  and  is  con- 
tinued into  the  cavity  beneath  pseudo-deltidium.  These  features  are  shown 
in  casts  and  in  transverse  sections  of  valve.  The  dorsal  valve  shows  a  double 
or  bilobed  cardinal  process  with  the  strong  crural  bases  supporting  spiral  arms, 
which  are  directed  into  the  two  compartments  of  the  ventral  valve,  and, 
making  numerous  turns,  terminate  in  the  rostral  part  of  the  shell. 

Formation  and  Locality. — This  species  is  found  in  the  Hamilton  group  in  different  localities.  At 
Widder  Station,  in  Canada  West,  it  occurs  in  great  abundance,  and  in  most  perfectly  preserved  specimens. 
In  the  Corniferous  group  around  the  Falls  of  the  Ohio  it  is  also  somewhat  abundant  in  good  but  silici- 
fied  specimens. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  97 

Cyrtina  hamiltoniae,  var.  recta,    HALL. 

Plate  XIII.,  figures  13  to  16. 
Oyriina  hamiltonensis,  var.  recta,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  270—1867. 

Prof.  Hall  separates  this  shell  from  the  species  Hamiltoniae,  and  makes  a 
variety  of  it,  which  is  based  upon  two  points :  first,  upon  the  plane,  flat  area 
and  straight  beak,  and  second,  upon  the  angular  plications.  If  only  the  ex- 
treme forms  were  in  existence,  those  points  would  suffice  to  maintain  the  new 
variety ;  but  inasmuch  as  the  species  Cyrtina  hamiltoniae  is  very  variable  in 
shape,  we  find  individuals  which  gradually  lead  from  one  form  to  the  other. 
Three  groups  may  be  distinguished  among  these  shells ;  in  the  first  we  find 
specimens  with  very  arcuate  or  concave  cardinal  area,  such  as  shown  in  figure 
11,  plate  13  ;  in  the  second  group  the  cardinal  area  is  only  slightly  curved  near 
the  beak,  and  the  latter  is  always  somewhat;  twisted  or  turned  to  one  side  ;  and 
in  the  last  group  we  find  the  forms,  separated  by  Prof.  Hall  from  the  main 
species,  and  put  in  the  variety  recta.  In  these  shells  the  cardinal  area  is 
always  plane  or  flat,  and  leaning  generally  towards  the  front,  and  the  beak  is 
without  any  curvature.  Intermediate  forms  connect  the  first  with  the  second 
group,  and  others  lead  from  the  second  to  the  third  group. 

Formation  and  Locality. — Found  associated  with  the  preceding  species. 

Genus  Meristella.    Han. 

Meristella,  Hall.     13th  Regent's  Report— 1860. 
Etymology :  a  diminutive  of  Merista. 

The  shells  of  this  genus  are  oval,  ovoid  or  sub-orbicular,  elongate  or  rarely 
transverse ;  valves  unequally  convex,  with  or  without  a  median  fold  or  sinus  ; 
beak  of  the  ventral  valve  often  with  a  circular  foramen  and  incurved  over  the 
umbo  of  the  dorsal  valve.  Area  none ;  valves  articulating  by  teeth  and 
sockets ;  surface  smooth  or  with  fine  concentric  lines  of  growth,  and  with 
very  fine,  indistinct  or  obsolete  radiating  striae. 

The  interior  of  the  dorsal  valve  is  marked  by  the  presence  of  a  strong 
hinge-plate  or  cardinal  process,  and  from  the  base  of  this  proceeds  a  thin, 
longitudinal  septum,  which  often  extends  for  half  the  length  of  the  valve. 
The  interior  of  the  ventral  valve  shows  a  triangular  fissure  below  the  beak, 
which  joins  a  semi-circular  perforation  at  the  apex.  At  the  base  of  this  fissure 
are  two  strong  teeth,  which  extend  in  thickened  or  slender  plates  to  bottom  of 
cavity,  and  curve  around  upper  part  of  the  muscular  area,  which  is  broadly 
triangular  or  ovate.  There  is  sometimes  a  thickening  of  the  shell  at  the  base 
of  the  rostral  cavity,  which  abruptly  limits  the  muscular  impression  ;  but  there 
is  neither  septum  nor  rudiment  of  one  as  in  Merista, 

QEOL.    SUK.— 13 


98  PALEONTOLOGY    OP    KENTUCKY. 

Meristella  nasuta.    C»NKAD. 

Plate  XV.,  figures  2  to  8. 

Atrypa  nasuta.,  Conrad.     Ann.  Kep.  on  Pal.  N".  Y.,  p.  18. 
Meristella  nasuta,  Hall.     Thirteenth  Rep.  on  St.  Cab.,  p.  93— 186t. 
Meristella  elissa,  Hall.     Fourteenth  Rep.  on  St.  Cab.,  p.  100—1861. 
Meristella  nasuta,  Hall.     Fifteenth  Rep.  on  St.  Cab.,  p.  160 — 1862. 
Athyris  clara,  Billings.     Canadian  Journ.,  p.  274 — 1860. 
Athyris  clara,  Geology  of  Canada,  p.  373 — 1863. 
Meristella  nasuta,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  299—1867. 

Shell  large,  sub-oval,  ovate  or  sub-rhomboidal ;  the  greatest  width  near  or  a 
little  below  the  middle ;  length  equalling  or  slightly  exceeding  width.  Both 
valves  convex,  the  ventral  one  rather  gibbous.  A  nasute  or  linguiform  exten- 
sion of  tiie  front  in  old  shells. 

Ventral  valve  exceeding  the  other  one  considerably  in  convexity  ;  point  of 
greatest  curvature  being  a  little  above  the  middle,  from  where  it  slopes  in 
strong  curves  towards  the  lateral  margins  and  to  the  cardinal  lines,  but  in 
somewhat  gentler  curves  to  the  front. 

Umbo  extremely  prominent;  beak  regularly  rounded  and  closely  incurved. 
The  anterior  portion  of  the  valve  is  produced  into  a  nasute  or  linguiform  ex- 
tension ;  no  depression  for  a  mesial  sinus  is  noticeable.  In  young  or  half  grown 
individuals  no  basal  extension  exists.  Dorsal  valve  less  convex  than  the  oppo- 
site, moderately  and  regularly  convex  in  young  shell,  becoming  in  old  shells 
gibbous  above,  curving  regularly  to  the  sides,  and  often  a  little  flattened  at  the 
baso-lateral  margins ;  at  about  the  middle  of  the  length,  or  sometimes  above, 
the  central  portion  of  the  valve  becomes  more  gibbous,  and  towards  the  front 
is  abruptly  elevated  into  a  rounded  prominent  fold,  corresponding  to  the  lin- 
guiform extension  of  the  opposite  valve.  The  beak  is  moderately  incurved, 
lying  close  beneath  that  of  the  opposite  valve. 

The  general  aspect  of  the  surface  is  that  of  a  smooth  shell  with  a  few  concen- 
tric lines  of  growth ;  in  perfect  individuals,  however,  the  entire  surface  is 
ornamented  by  very  fine  concentric  lines,  and  usually  by  indistinct  radiating 
striae,  which  are  often  more  conspicuous  in  the  partially  exfoliated  shell,  and 
still  more  distinct  in  some  of  the  casts.  The  interior  of  the  ventral  valve  pre- 
serves the  generic  characters  in  a  marked  degree,  in  the  open  fissure  beneath 
the  beak,  which  is  terminated  by  a  sub-circular  perforation  ;  in  the  strong 
dental  plates,  and  deeply  marked  muscular  impression.  The  inner  surface, 
surrounding  the  muscular  impression  is  covered  by  radiating  striae.  The 
interior  of  the  dorsal  valve  shows  a  strong  cardinal  process,  with  a  shallow, 
spoon-shaped  depression  in  center,  margined  by  deep  teeth  sockets.  The  mus- 
cular area  is  elongate-ovate,  broader  above,  and  divided  through  the  center  by 
a  thin  elevated  septum. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  99 

This  shell  is  described  by  Mr.  Billings,  of  the  Canadian  Geological  Survey, 
under  the  name  of  Athyris  clara,  but,  inasmuch  as  Mr.  Conrad's  name  of 
Atrypa  nasuta  preceded  that  of  Mr.  Billings,  his  species  has  priority,  while 
that  of  Billings  must  be  dropped. 

Both  in  general  exterior,  form  and  internal  characters,  this  species  bears 
much  resemblance  to  Meristella  (Atrypa)  tumida  of  Dalman,  but  in  Dalman's 
species  there  is  a  distinct  sinus  in  the  ventral  valve,  while  the  umbo  is  more 
gibbous,  the  beak  larger  and  more  incurved,  and  the  entire  shell  is  compara- 
tively more  ventricose.  The  muscular  area  in  the  ventral  valve  is  of  the  same 
shape,  but  narrower  than  the  prevailing  form  in  our  species. 

Formation  and  Locality. — Found  in  the  upper  strata  of  the  Devonian  group  at  and  around  the 
Falls  of  the  Ohio  in  Kentucky  and  Indiana.  It  is  of  rather  rare  occurrence,  and  fair  specimens  still  more 
so. 

Meristella  unisulcata.     CONRAD. 

Plate  XV.,  figures  9  to  16. 

Atrypa  unisulcata,  Conrad.    Ann.  Rep.  on  the  Pal.  of  N.  Y.,  p.  56 — 1841. 
Rhynchonella  unisulcata  (Conrad  sp.),  Hall.     Tenth  Rep.  St.  Cab.,  p.  125 — 1857. 
Atrypa  unisulcata,  referred  with  doubt  to  Meristella,  and   name  Goniocoelia  proposed  in  Fourteenth  Rep. 

St.  Cab.,  p.  101—1861. 

Compare:  Pentagonia  peersii,  Cozzens.     Ann.  of  N.  Y.  Lye.,  Vol.  III.,  p.  158 — 1846. 
Meristella  unisulcata,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  309,  pi.  L.— 1867. 

Shell  of  medium  size,  sub-trigonal,  quadrilateral  or  sometimes  sub-pentago- 
nal in  outline;  wider  in  front,  with  the  sides  sometimes  sloping  from  the  beak, 
but  in  others  the  hinge-line  is  extended  nearly  straight,  and  the  sides  rectangu- 
lar to  it.  A  wide  mesial  depression  on  one  side  with  prominent  elevation. 

Ventral  valve,  with  a  broad,  deep  mesial  sinus,  which  occupies  nearly  whole 
width  of  valve,  and  is  bounded  on  either  side  by  an  angular  elevation,  which 
extends  from  beak  to  baso-lateral  angles.  The  portion  of  the  valve,  outside  of 
limitation  sinus,  is  abruptly  inflected  upwards  or  towards  the  dorsal  valve, 
often  nearly  at  right-angles.  Umbo  is  prominent,  and  beak  is  incurved  over 
umbo  of  dorsal  valve. 

Dorsal  valve  gibbous  in  the  middle ;  the  center  occupied  by  a  prominent 
mesial  fold,  from  which  the  surface  slopes  abruptly  to  the  lateral  angles,  be- 
coming more  or  less  concave  within  the  lateral  and  cardino-lateral  margins. 
The  mesial  fold  is  marked  along  the  center  by  a  single  deep  groove,  which 
extends  to  the  beak  of  the  valve.  Surface  marked  by  fine  concentric  striae, 
and  sometimes  by  strong  imbricating  folds  ;  there  are  also  slight  indications  of 
interrupted  radiating  striae.  The  specimens  of  our  limestone  are  either  exfoli- 
ated or  silicified;  in  both  cases  the  finer  markings  are  obliterated.  The  interior 
of  the  ventral  valve,  specimens  of  which  are  found  in  an  excellent  state  of  pres- 


100  PALAEONTOLOGY    OF    KENTUCKY. 

ervation,  shows  a  perforation  in  the  beak,  opening  below  into  an  angular 
space,  which  has  been  occupied  by  the  beak  of  the  other  valve,  and  thence 
communicating  with  the  main  cavity  of  the  valve.  The  base  of  the  fissure  is 
margined  on  each  side  by  a  strong  tooth,  which  extends  in  strong  dental  plates 
to  bottom  of  cavity,  and  these  are  often  continued  in  a  thickened  ridge  bor- 
dering the  muscular  impression.  The  imprints  of  the  adductor  muscles  are 
opposite  the  base  of  the  dental  plates,  and  below  and  on  either  side  are  the 
imprints  of  the  broad  divaricator  muscle.  In  dorsal  valve,  cardinal  process  is 
broad  and  strong  ;  crural  bases  somewhat  widely  diverging  and  center  abruptly 
depressed.  The  teeth  sockets  are  large,  and  supported  by  strong  lamellar  cal- 
losities, which  extend  along  inner  side  of  the  valve  nearly  parallel  to  the  ex- 
terior margin.  The  muscular  imprints  are  divided  by  a  low  distinct  septum. 
This  shell  presents  considerable  variation  in  its  form  and  general  aspect, 
though  always  preserving  its  unmistakable  character.  In  young  and  half 
grown  shells,  where  the  hinge-line  is  but  little  extended,  it  has  a  general  tri- 
angular form.  When  the  hinge-line  becomes  extended,  and  the  sides  nearly 
straight,  with  a  moderately  curving  base,  it  is  quadrangular.  Some  specimens 
assume  the  shape  of  a  hexagon,  others  of  a  pentagon.  In  some  individuals 
there  is  a  slight  elevation  in  center  of  sinus,  but  this  is  of  rare  occurrence, 
oftener  the  sinus  contains  a  central  rounded  depression,  margined  by  a  slight 
elevation,  which  extends  from  beak  to  front.  The  beak  of  the  ventral  valve 
is  sometimes  not  closely  pressed  upon  the  dorsal  umbo,  but  in  most  specimens 
is  such  the  case,  and  oftentimes  to  such  a  degree  that  the  apex  is  incurved  into 
the  groove  of  the  mesial  fold.  On  the  dorsal  valve  we  find  two  considerable 
elevations,  one  on  each  side  of  the  mesial  fold ;  they  start  from  the  cardino- 
lateral  margins,  near  to  which  they  have  their  maximum  elevation,  gradually 
decreasing  until  they  disappear  in  the  surface  of  the  valve  a  little  above  its 
middle ;  their  direction  is  not  quite  parallel  to  the  mesial  groove,  but  is  deflect- 
ing outwards.  (Copied  from  Hall's  description,  with  many  alterations  of  my 
own.) 

Formation  and  Locality. — Found  in  the  upper  strata  of  the  Corniferous  group  surrounding  the 
Falls  of  the  Ohio,  in  Kentucky  and  Indiana,  where  fractions  of  this  species  are  pretty  abundant  in  some 
localities,  but  fine  and  well  preserved  specimens  of  the  whole  shell,  as  well  as  of  single  valves,  which  are 
found,  are  exceedingly  rare.  My  cabinet  contains  some  exquisite  examples  of  this  species.  The  fossils  ot 
the  Corniferous  strata,  from  the  neighborhood  of  the  Falls,  are,  on  the  Indiana  side  of  the  river,  generally 
more  numerous,  and  in  the  average  better  preserved,  than  those  found  in  Kentucky.  The  little  town 
Charlestown,  in  Clarke  county,  Indiana,  two  or  three  miles  off  the  river,  is  about  the  center  of  one  of  the 
richest  fields  of  the  Devonian  formation,  which  has  furnished  a  great  many  cabinets  with  very  choice  speci- 
mens. A  day's  rambling  in  the  washes  of  the  fields  around  Charlestown,  after  several  days'  hard  rain,  is 
a  real  treat  to  any  geologist,  and  never  fails  to  fill  his  basket  with  fine  shells,  beautiful  corals,  and  some- 
times, but  not  very  often,  with  rare  crinoids. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  101 

Genus  Meristina.    Han. 

MeriaKna,  Hall.     20th  Regent's  Keport— 1867. 

Etymology:  Merista,  a  genus  of  shells;  inus,  implying  resemblance. 

The  shells  of  this  genus  resemble  in  shape  and  general  aspect  those  of  Mer- 
istella  ;  they  differ  only  from  the  latter  by  internal  arrangement  of  the  loops. 
The  lamellae  of  the  shells  of  this  genus  are  united  by  a  single  loop  only.  This 
interior  arrangement  is  observed  in  Meristina  maria  and  M.  nitida,  both  of  the 
Magara  group.  In  neither  of  these  species  is  there  any  indication  of  acces- 
sory lamellae,  as  in  Athyris,  nor  evidence  of  the  extension  of  the  loop  beyond 
a  certain  point.  The  simple  character  of  the  spires  in  these  forms  are  of 
sufficient  value  to  constitute  a  new  genus,  that  of  Meristina. 

Meristina  maria.    HALL. 

Plate  XXIX.,  figures  7,  8,  9  and  10. 

Mcristella  maria,  Hall.     Trans.  Alb.  Inst.,  Vol.  IV.,  p.  212—1863. 
Meristina  maria,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  299—1867. 
Meristina  maria,  Hall.     28th  Bep.  N.  Y.  St.  Mus.,  Mus.  Edit.,  p.  159—1879. 
Meristina  maria,  Hall,    llth  Geol.  Kep.  of  Ind.,  p.  299—1881. 

Shell  of  large,  at  least  of  more  than  medium  size,  ventricose,  broadly  ovate 
or  subquadrangular ;  length  and  width  usually  equal ;  greatest  width  at  one 
third  of  length  from  base  or  front.  Ventral  valve  gibbous  in  the  upper  half, 
having  a  slight  elevation  from  beak  to  middle  of  valve,  where  it  becomes  de- 
pressed and  sinuate,  and  abruptly  deflected  upward  into  a  linguiform  basal 
extension,  from  the  point  of  greatest  convexity,  which  is  a  little  above  middle 
of  valve;  it  slopes  gently  to  lateral  and  basal  margins,  but  more  abruptly  to  the 
cardinal  margins,  at  which  the  cardinal  borders  are  inflected.  Umbo  is  prom- 
inent, and  beak  strongly  incurved  upon  the  umbo  of  other  valve.  Dorsal  valve 
gibbous,  greatest  convexity  below  umbo,  from  where  it  slopes  abruptly  to 
cardinal  margins,  but  in  a  gentle  curve  to  the  lateral  and  basal  margins  ;  a  sub- 
angular  ridge  extends  from  beak  to  front,  near  which  it  increases  rapidly  in 
width  and  elevation,  thus  forming  a  prominent  but  undefined  mesial  fold ; 
umbo  moderate,  and  beak  strongly  incurved  under  that  of  other  valve. 

Surface  marked  by  strong,  concentric  lines  of  growth.  Interior  of  ventral 
valve  marked  by  two  strong  diverging  dental  lamellae,  which  extend  to  near 
the  middle,  limiting  a  deep,  triangular  muscular  cavity. 

This  species  is  most  nearly  related  to  Meristella  (Merista)  tumida  of  Euro- 
pean authors,  but  is  less  rotund,  while  that  species  does  not  possess  the  pecu- 
liar flattening  of  the  cardinal  half  of  the  ventral  valve,  and  its  accompanying 


102  PALEONTOLOGY    OF    KENTUCKY. 

subangular  ridge.  It  differs  from  all  other  species  of  the  Niagara  and  Lower 
Helderberg  groups,  but  approaches  in  some  characters  to  Meristella  (Atrypa) 
crassirostrata  of  the  Niagara  group.  From  Meristina  nitida,  with  which  it  is 
usually  associated,  it  differs  greatly,  and  is  therefore  easily  distinguished. 

Formation  and  Locality. — Found  in  the  Niagara  strata  in  the  quarries  east  of  the  city  of  Louis- 
ville, Ky.,  where  it  is,  however,  somewhat  rare,  at  least  in  well  preserved  specimens,  while  at  Waldron, 
Indiana,  it  occurs  in  great  abundance,  and  of  great  beauty  and  perfection. 

Meristina  nitida.    HALL. 

Plate  XXXIII..  figures  10  and  11. 

Atrypa  nitida,  Hall.     Geol.  of  N.  Y.,  Geol.  Sur.  4th  dist.,  Tab.  of  Org.  Remains,  p.  11—1848. 
Atrypa  nitida,  Hall.     Pal.  N.  Y.,  Vol.  II.,  p.  268,  pi.  65—1852. 
Merista  nitida,  Hall.     12th  Eep.  St.  Cab.  Nat.  Hist.,  p.  78—1859. 
Meristella  nitida,  Hall.     Trans.  Alb.  Inst.,  Vol.  IV.,  p.  226—1863. 
Meristina  nitida.  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  299—1867. 
Meristina  nitida,  Hall.    28th  Eep.  N.  Y.  St.  Mus.,  Nat.  Hist.  Edit.,  p  160—1879. 
Meristina  nitida,  Hall,     llth  Geol.  Eep.  of  Indiana,  p.  300—1881. 

Shell,  as  found  in  the  neighborhood  of  Louisville,  of  small  size ;  those  found 
at  Waldron,  Indiana,  of  medium  size,  sub-triangular,  with  a  sinuate  base  and 
largely  extended  beaks ;  most  of  the  shell  only  moderately  convex,  but  some 
becoming  very  gibbous,  even,  in  isolated  instances,  per-gibbous ;  lateral  and 
basal  margins  broad  and  square,  owing  to  the  fact  that  in  both  valves  the  mar- 
ginal borders  inflect  almost  rectangularly.  Only  in  few  individuals  do  both 
valves  slope  regularly  without  inflection  to  their  edges,  and  meet  under  an 
acute  angle  (see  figures  10  and  11,  plate  33).  Ventral  valve  usually  of  equal 
convexity  with  dorsal,  showing  in  its  basal  third  a  slight  depression,  which 
terminates  in  basal  inflection  or  emargination ;  the  beak  is  much  elevated  above 
and  incurving  over  beak  of  the  opposite  valve 

Dorsal  valve  has  no  indication  of  a  mesial  elevation  ;  its  beak  is  strongly 
incurved  into  ventral  valve.  There  are  no  surface-markings  except  a  few  con- 
centric lines  of  growth. 

Formation  and  Locality. — It  occurs  usually  associated  with  Meristina  maria  in  the  Niagara  strata 
east  of  the  city  of  Louisville,  Ky.;  it  is,  however,  not  as  rare  as  that  species,  but  is  found  pretty  abundantly 
and  also  in  very  small  but  well  preserved  specimens.  Shells  of  this  species  from  Waldron,  Indiana,  are 
often  of  more  than  double  size  of  even  our  largest  individuals.  This  species  is  easily  identified,  inasmuch 
as  it  differs  considerably  from  all  other  species  of  the  Upper  Silurian  formation.  The  shells  figured  are 
different  from  the  usual  forms. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  103 

Genus  Nucleospira.    Han. 

Nucleospira,  Hall.     Pal.  N.  Y.,  Vol.  III.,  page  219—1869. 

Etymology:  nucleus,  a  kernel;  spira,  a  spire,  alluding  to  the  internal  spire  of  these  shells. 

Shell  spheroidal  or  transversely  elliptical,  more  or  less  gibbous  or  ventricose, 
furnished  with  internal  spires,  as  in  Spirifer.  Hinge-line  shorter  than  width 
of  shell ;  cardinal  extremities  rounded.  Valves  sub-equal,  articulating  by 
teeth  and  sockets.  Ventral  beak  extended  beyond  the  dorsal,  and  beneath  it 
a  triangular  depression  or  area,  which  sometimes  terminates  in  a  shallow, 
spoon-shaped  pit,  on  each  side  of  which,  at  the  base,  is  a  strong  tooth.  A 
narrow  ridge  or  septum  extends  along  the  center  of  inner  side  of  valve  from 
beak  to  base. 

Dorsal  valve  furnished  with  a  strong,  spatulate,  cardinal  process,  which, 
rising  vertically  from  cardinal  margin,  is  closely  grasped  at  its  base  by  the  car- 
dinal teeth  of  other  valve,  and  thence  bending  abruptly  upwards,  and  expand- 
ing, is  projected  into  the  cavity  of  other  beak,  lying  close  upon  under  side  of 
false  area.  This  process  is  grooved  or  depressed  in  the  center  of  the  upper 
side,  so  as  to  leave  between  it  and  the  arch  of  the  ventral  beak  a  narrow  space 
for  the  passage  of  a  pedicle,  for  protrusion  of  which  a  minute  foramen  is 
sometimes  observed  in  beak.  From  the  sides  of  this  process,  above  the  junc- 
tion of  teeth  of  other  valve,  and  at  the  point  where  it  bends  upward,  originate 
the  brachial  processes,  which  support  the  spires.  A  deep  cavity  beneath  the 
cardinal  process  extends  to  dorsal  beak,  from  which  originates  a  thin  elevated 
septum,  running  to  base  of  shell.  Muscular  imprints  confined  to  a  narrow, 
oval  space.  Surface  smooth ;  shell  structure  punctate,  and,  when  perfect, 
covered  with  minute  hair- like  spines. 

Nucleospira  concinna.    HALL. 

Plate  XXXII.,  figures  1,  2,  3  and  4. 

Atrypa  concinna,  Hall.     Geol.  Rep/4th  Dist.  of  N.  Y.,  p.  200—1843. 
Nucleospira  concinna,  Hall.     Twelfth  Rep.  on  St.  Cab.,  p.  25 — 1859. 
Nucleospira  concinna,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  279—1867. 

Shell  small,  depressed,  sub-spheroidal,  nearly  circular  in  outline ;  width 
being  usually  a  little  greater  than  length ;  valves  sub-equal.  Ventral  valve 
regularly  convex,  greatest  convexity  a  little  above  middle,  and  curving  regu- 
larly to  the  sides  and  front ;  umbo  prominent ;  beak  neatly  pointed  and  in- 
curved over  apex  of  dorsal  valve,  leaving  a  space  between  which  sometimes 
exposes  the  narrow  area.  There  is  usually  a  narrow  depressed  line  from  beak 
to  base  of  valve ;  but  this  is  often  absent,  or  so  faint  as  not  to  be  readily  ob- 
served. Dorsal  valve  regularly  convex,  sometimes  gibbous,  becoming  a  little 


104  PALAEONTOLOGY    OF    KENTUCKY. 

depressed  towards  base ;  the  greatest  convexity  a  little  above  middle  of  valve. 
The  hinge-line  is  about  one-third  and  sometimes  one-half  as  long  as  width  of 
shell.  Surface  usually  smooth  or  very  finely  papillose ;  but  in  perfect  speci- 
mens the  surface  is  covered  by  numerous  fine  setae,  which  are  matted  together, 
and  the  interstices  being  filled  with  clay,  it  has  a  rough  appearance  while 
under  a  lens;  these  setae  give  a  finely  striate  aspect.  Beneath  the  fine  papillose 
surface  the  texture  of  the  shell  is  minutely  punctate. 

Formation  and  Locality. — Found  occasionally  in  the  Corniferous  limestone  at  and  around  the  Falls 
of  the  Ohio,  in  Kentucky  and  Indiana.  It  is  a  rather  rare  shell. 

Nucleospira  elegans.    HALL. 

Nucleospira  elegans,  Hall.     Pal.  N.  Y.,  Vol.  III.,  p.  222—1859. 

Shell  sub-orbicular,  wider  than  long.  Lateral  margins  strongly  curved,  baso- 
lateral  margins  very  slightly  curved,  almost  straight.  Central  third  of  the 
base  somewhat  prolonged  or  produced,  and  straight.  Ventral  valve  moderately 
convex,  except  in  the  umbonal  region,  which  is  somewhat  gibbous.  There  is 
sometimes,  on  the  elevated  center,  a  flattened  or  faintly  depressed  mesial  line 
from  umbo  to  base  ;  beak  elevated  above  that  of  the  opposite  valve  and  closely 
incurved  upon  it.  Area  usually  covered  by  the  incurved  beak,  but  sometimes 
visible.  Dorsal  valve  depressed  convex,  but  sometimes  almost  as  convex  as  the 
ventral ;  more  elevated  in  the  umbonal  region ;  beak  small,  strongly  incurved 
beneath  the  beak  of  the  opposite  valve.  Surface  of  the  shell  finely  and  beau- 
tifully punctate,  and  sometimes  preserving  remains  of  its  former  pilose  cover- 
ing. Some  specimens  of  this  species,  showing  the  cardinal  area,  might  be 
mistaken  for  Orthis. 

Formation  and  Locality. — Occurs  in  the  Niagara  limestone  east  of  the  city  of  Louisville.  A  large 
specimen  measures  eight  lines  in  width  by  seven  in  length,  while  a  smaller  one  has  a  width  of  six  lines  by 
a  length  of  five. 

Nucleospira  pisiformis.    HALL. 

Plate  XXXIII.,  figures  7,  8  and  9. 
Orthis  pisum,  Hall.     Pal.  N.  Y.,  Vol.  II.,  p.  250—1852. 
Nucleospira  pisiformis,  Hall.     Pal.  N.  Y.,  Vol.  III. — 1859. 
Nucleospira  pisiformis,  Hall.     Trans.  Alb.  Inst.,  Vol.  IV.,  p.  226 — 1863. 
Nucleospira  pisiformis,  Hall.    28th  Regent's  Rep.,  p.  160 — 1879. 
Nucleospira  pisiformis,  Hall,     llth  Geol.  Rep.  of  Ind.,  p.  302 — 1881. 

Shell  small,  sub-globose ;  valve  nearly  equal,  each  valve  with  as  light  de- 
pression down  the  center.  Ventral  valve  somewhat  more  convex,  and  beak 
more  elevated  than  in  the  dorsal.  Area  narrow,  small,  scarcely  extending 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  105 

beyond  width  of  beaks  at  their  base.  Surface  marked  by  fine  concentric  striae, 
usually  obscured  by  the  covering  of  minute,  hair-like  spines,  which,  when 
removed,  leave  a  punctate  surface. 

Formation  and  Locality. — Occurs  abundantly  at  Waldron,  Indiana,  and  rarely  in   the  quarries 
east  of  Louisville ;  in  the  Niagara  limestone  of  both  places. 


Genus  Spirifera. 

^~ Spirifera,  Sowerby.     Min.  Couch.,  Vol.  II. — 1815. 
Etymology:  spira,  a  spire;  fera,  to  bear. 

Shell  structure  fibrous  and  impunctate  ;  form  very  variable,  but  typical; 
more  or  less  three-sided  or  quadrate,  sometimes  oval  or  sub-circular.  Hinge- 
line  straight,  mostly  as  long  as,  or  longer  than  greatest  width  of  shell, 
sometimes  shorter.  The  cardinal  angles  sometimes  obtusely  rounded,  more 
commonly  produced  and  extended,  sometimes  greatly  so.  Surface  usually 
with  radiating  ribs,  or  smooth  or  striated.  Generally  an  elevated  fold  in  one 
valve,  and  a  corresponding  sinus  in  the  other.  Valves  articulated  by  teeth 
and  sockets.  Ventral  valve  the  larger,  with  a  more  or  less  prominent  beak,  a 
well  marked  area  and  a  triangular  foramen,  which  is  sometimes  closed  by 
a  pseudo-deltidium.  Dorsal  valve  with  a  narrow  area,  and  a  wide  triangular 
foramen.  Interior  more  or  less  occupied  by  two  spirally  rolled  lamellae,  form- 
ing two  cones,  the  apices  of  which  are  directed  towards  the  cardinal  angles. 

Spirifera  acuminata.    CONRAD. 

Plate  VIII.,  figures  1  to  8. 

Delthyris  acuminata,  Conrad.     Ann.  Rep.  of  Pal.  of  N.  Y.,  p.  65 — 1839. 
Spirifera  acuminata,  Conrad.     Hall  in  10th  Rep.  on  State  Cab.,  p.  135 — 1857. 
Spirifera  acuminata,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  198,  plate  29. 

Shell  large,  ventricose,  transverse,  with  the  hinge-line  usually  less  than  width 
of  shell ;  cardinal  extremities  rounded  or  truncate,  having  a  sub-elliptical  or 
sub-quadrate  outline  ;  mesial  fold  and  sinus  extreme.  Surface  plicated.  Ven- 
tral valve  variably  convex  on  two  sides,  with  a  wide  mesial  sinus,  which  is  well 
defined  in  the  upper  part,  becomes  wider  and  deeper  and  less  distinctly  de- 
fined in  middle  of  shell,  and  is  produced  in  front  into  a  long  triangular  exten- 
sion, curving  abruptly  from  the  greatest  convexity  to  sides  and  cardinal 
angles ;  umbo  prominent,  with  the  apex  incurved  over  the  wide  triangular  fis- 
sure ;  area  extending  to  cardinal  angles,  with  margin  rounded  except  towards 
the  extremities. 

Dorsal  valve  gibbous,  highly  elevated  in  middle  into  a  strong  angular  mesial 
fold,  and  curving  from  sides  of  fold  to  margin  of  shell,  except  at  the  cardinal 

UEOL.   SUK. — 14 


106  PALAEONTOLOGY    OF    KENTUCKY. 

angles,  where  it  is  a  little  flattened  and  projecting,  so  as  to  give  a  minute  artic- 
ulate appearance  ;  summit  of  mesial  fold  regularly  arcuate  from  beak  to  base  : 
apex  lightly  incurved  over  the  narrow,  nearly  vertical  area. 

Surface  on  either  side  of  the  fold  or  sinus  marked  by  from  sixteen  to  twenty 
plications,  about  four  or  five  of  which,  nearest  to  the  center,  are  dichotomous 
from  below  the  middle  of  their  length  ;  plications  low  and  rounded  above  and 
flattened  below  middle,  those  towards  the  margin  very  slender ;  first  ten  or 
twelve  ribs  on  each  side  of  the  fold  or  sinus  occupy  greater  part  of  shell.  The 
entire  surface  is  marked  by  delicate  concentric  striae,  which  are  often  crowded 
into  imbricating  lamellose  lines  towards  front  of  shell.  In  very  perfect  speci- 
mens these  concentric  striae  are  papillose  or  fimbriated  by  fine  radiating  striae. 
These  fine  surface-markings,  however,  are  usually  nearly  or  quite  obliter- 
ated. 

The  interior  of  ventral  valve  shows  but  a  partial  thickening  of  the  shell  in 
rostral  cavity ;  teeth  are  strong  and  short,  dental  plates  spreading  and  margin- 
ing the  upper  part  of  the  ovate  muscular  area,  which  is  broader  above,  and 
sometimes  very  much  resembles  this  feature  in  S.  striatus. 

The  casts  preserve  strong  and  prominent  marks  of  the  muscular  impressions, 
and  sometimes  vascular  markings  outside  of  the  muscular  area,  while  in  other 
individuals  the  papillose  ovarian  markings  are  very  distinctly  preserved.  In 
the  cast  of  the  dorsal  valve  there  are  sometimes  strong  impressions  of  the  oc- 
clusor  muscular  markings,  and  the  apex  also  show  the  striae  of  the  cardinal 
muscular  attachment.  (Hall.) 

This  species  has  some  similarity  with  Spir.  macrothyris,  but  is  easily  dis- 
tinguished from  this  and  all  the  other  Spirifera  of  our  strata  by  its  extremely 
elevated  angular  mesial  fold  and  deep  sinus,  which  are  bounded  by  the  dichoto- 
mous plications.  The  size  of  this  species  is  very  variable;  it  measures  from  one 
inch  to  two  and  a  quarter  inch  in  width,  and  from  three-fourths  of  an  inch  to 
an  inch  and  seven-eighths  in  length. 

Spir.  acuminata  is  considered  by  the  European  geologists,  Dr.  F.  Roemer 
and  M.  de  Verneuil,  as  identical  with  the  Spirifera  cultrijugata  of  Europe ; 
but  Mr.  Davidson,  the  eminent  English  Palaeontologist,  has  pointed  out  the 
fact  that  the  American  species  has  bifurcating  plications,  which  are  not  seen 
in  Roemer' s  figures  of  the  European  species,  and  also  that  the  European  shell 
has  less  plications  than  the  American.  Here  again  the  figures  are  used  to  de- 
termine the  similarity  and  dissimilarity  of  two  shells.  The  figures  may  not 
be  correct,  or  it  is  also  possible  that  the  specimen  from  which  Mr.  Roemer  drew 
his  picture,  like  many  of  our  species,  did  not  show  dichotomous  ribs.  Even 
Mr.  Conrad,  who  first  described  Spir.  acuminata,  did  not  mention  the  bifurcated 
plications,  showing  that  either  his  specimens  did  not  possess  them  at  all,  or 
only  in  such  a  faint  condition  that  Mr.  Conrad  did  not  notice  them.  Mr. 


FOSSILS    OF    THE    SILUEIAN    AND    DEVONIAN    ROCKS. 

Roemer's  species  is  very  rare  in  Germany,  making  it  difficult  to  procure  speci- 
mens showing  the  exact  features  of  perfect  shells.  From  these  facts  we  must 
draw  the  conclusion  that  both  species  are  either  identical,  or  that  one  is  only 
a  variety  of  the  other.  In  this  case  Mr.  Conrad's  species  has  the  priority  over 
Roemer's  and  Spir.  acuminata  would  be  maintained,  even  if  its  similarity  with 
Sp.  cultrijugatax  were  admitted.  Figures  7  and  8,  plate  8,  show  a  very  fine 
internal  cast  of  this  species. 

Formation  and  Locality. — Pound  abundantly  and  in  good  condition  in  the  Devonian  limestone  of 
Kentucky  and  Indiana,  around  the  Falls  of  the  Ohio. 

Spirifera  atwaterana.    s.  A.  MILLER. 

Plate  IX.,  figures  1  to  7. 
Spirifer  pennatus  and  Spirifer  ligus.  Owen.     Geol.   Kep.  of  Wisconsin,  Iowa   and   Minnesota,  p.  585,  pi. 

III.,  figs.  3,  4  and  8—1852. 

Spirifer  pennatus,  Hall.     Geology  of  Iowa,  Vol.  I.,  Part  II.,  p.  510,  pi.  5 — 1858. 
Spirifer  ativaterana,  S.  A.  Miller.     Proc.  Davenport  Acad.  Sci. — 1878. 

This  species  is  generally  known  under  the  name  of  Spir.  pennata ;  but  this 
specific  designation  was  used  already  in  1820  by  Atwater  for  another  Spirifera, 
and,  therefore,  another  name  had  to  be  adopted  for  this  shell.  S.  A.  Miller, 
Esq.,  of  Cincinnati,  Ohio,  named  it  atwaterana. 

This  species  belongs  to  the  large  sized  Spirifera ;  in  width  it  is  not  exceeded 
by  any  other  kind  ;  it  is  very  variable  in  form,  from  sub-globose  to  transverse 
and  broadly  triangular  semi-circular,  or  semi-elliptical,  sometimes  inequi- 
lateral ;  hinge-line  always  more  or  less  extended  into  wing-like  expansions, 
resembling  in  this  feature  Spir.  mucronata  ;  valves  mostly  equally  convex. 

Ventral  valve  most  convex  in  the  middle  and  on  the  umbo ;  beak  much 
elevated  above  the  hinge-line,  more  or  less  pointed  and  slightly  incurved. 
Mesial  sinus  [strongly  defined  at  margins,  rapidly  widening  towards  base,  and 
produced  in  an  angular  extension  in  front.  Area  large  and  extending  to  cardi- 
nal extremities^;  concave  and  striated  vertically  and  longitudinally ;  foramen 
large  and  open  to  apex,  and  forming  an  equilateral  triangle. 

Dorsal  valve  also  most  gibbous  in  the  middle  and  on  the  umbo  ;  beak  mark- 
edly incurved  ;  valve  curves  from  the  point  of  the  greatest  convexity  regularly 
to  anterior  and  lateral  margins,  and  is  more  or  less  compressed  at  cardinal 
angles ;  mesial  fold  is  strongly  elevated,  sometimes  a  little  flattened  on  top, 
and  often  sub  angular  towards  front. 

Surface  marked  by  from  fifteen  to  twenty-five,  or  even  more  simple,  rounded 
plications  on  each  side  of  mesial  fold  and  sinus  ;  central  ribs  are  much  stronger 
than  lateral  ones ;  of  the  former  only  about  six  to  eight  on  each  side  reach 
apex,  all  others  run  out  on  the  margins  of  the  cardinal  area.  In  well  preserved 


108  PALAEONTOLOGY    OF    KENTUCKY. 

specimens  the  entire  surface  is  ornamented  by  slender  radiating, striae,  which, 
however,  are  not  visible  in  most  specimens.  Concentric  lamellose,  imbricating 
lines  of  growth  are  numerous  in  some  specimens,  while  others  show  very  few 
or  even  none  at  all. 

Formation  and  Locality. — Found  rarely,  and  seldom  well  preserved,  in  the  upper  strata  of  the 
Devonian  limestone  around  the  Falls  of  the  Ohio,  in  Kentucky  and  Indiana. 

Spirifera  arctisegmenta.    HALL. 

Plate  XII.,  figures  14  and  15. 

Spirifer  arctisegmentus,  Hall.     Tenth  Rep.  on  State  Cab. — 1867. 
Spirifer  arctisegmenta,  Hall.     Descript.  of  Hew  Pal.  Fossils,  p.  91 — 1857. 
Spirifer  arctisegmenta,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  208,  pi.  81. 

Shell  transversety  semi-oval ;  length  equal  or  less  than  one-third  of  width ; 
hinge-line  equal  to  greatest  width  of  shell,  and  terminating  in  salient  angles 
or  mucronating  points.  Ventral  valve  the  more  convex;  most  convex  at  the 
umbo,  from  which  it  slopes  regularly  to  anterior  and  lateral  margins ;  mesial 
sinus  angular  and  distinctly  defined  quite  to  apex  of  shell ;  beak  not  incurved ; 
area  flat  and  straight  and  a  little  inclined  towards  the  front.  The  lateral  view 
given  of  this  shell  in  figure  15,  plate  12,  is  incorrect,  by  showing  the  area  con- 
cave and  inclined  towards  the  rear.  Fissure  narrow  and  open  to  apex. 

Dorsal  valve  depressed  convex,  scarcely  flattened  towards  the  cardinal  ex- 
tremities ;  beak  and  central  portion  of  the  shell,  together  with  the  linear  area, 
slightly  incurved. 

The  surface  is  marked  by  from  five  to  eight  or  nine  angular  plications  on 
each  side  of  the  fold  or  sinus,  which  on  the  ventral  valve  are  slightly  curved 
towards  the  front,  and  of  which  only  about  three  reach  the  beak,  while  the 
balance  run  out  along  the  margins  of  the  cardinal  area,  where  they  coalesce 
with  an  elevated  ridge,  which  borders  the  area.  The  plications  on  the  dorsal 
valve  are  pretty  direct ;  fine,  close,  concentric,  undulating  striae  mark  the 
entire  surface. 

This  shell  may  be  distinguished  from  Sp.  segmenta,  as  well  as  from  other 
allied  forms,  by  its  larger  and  more  angular,  as  well  as  less  numerous  pli- 
cations, and  in  having  a  distinct  linear  ridge  along  margin  of  area  of  ventral 
valve ;  its  foramen  is  likewise  narrower,  and  its  sinus  deeper  and  more  angular 
than  in  Spir.  segmenta.  (Hall.) 

Formation  and  Locality — Found  in  the  Corniferous  limestone  at  and  around  the  Falls  of  the  Ohio 
in  Kentucky  and  Indiana,  where  it  is,  however,  of  rare  occurrence,  especially  in  well  preserved  speci- 


mens. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  109 

Spirifera  byrnesi.     *.  SP. 

Plate  X.,  figures  1-5,  31-34  and  36-39. 

Shell  sub  quadrate,  semi-circular  and  gibbous  in  outline;  hinge-line  equalling 
greatest  width  of  shell  and  terminating  in  salient  angles.  Surface  plicate. 

Ventral  valve  ventricose  and  only  little  more  gibbous  than  other  valve;  regu- 
larly arcuate  from  beak  to  front ;  greatest  convexity  in  the  upper  part  a  little 
above  the  middle,  from  where  it  curves  regularly  to  the  front  and  sides  ;  beak 
much  elevated  above  hinge-line,  and  slightly  arcuate.  Cardinal  area  high, 
concave,  and  extending  to  cardinal  angles,  where  it  never  forms  an  acute  angle, 
but  shows  always  a  height  of  from  one-quarter  to  one- half  of  a  line,  a  feature 
which  is  not  sufficiently  expressed  in  the  figures  on  plate  10 ;  mesial  sinus 
sharply  defined,  forming  a  deep  triangular  groove,  with  an  acute  angle  at  the 
bottom,  much  produced  in  front ;  fissure  of  medium  size. 

Dorsal  valve  gibbous,  with  a  greatly  elevated  mesial  fold,  which  is  edged  in 
its  upper  part  and  rounded  below  ;  beak  little  elevated  and  slightly  inclined 
over  a  narrow  hinge-area.  Surface  marked  by  from  eight  to  ten  very  prominent 
and  angular  plications  on  each  side  of  the  mesial  fold  and  sinus,  which  are 
crossed  by  strong  imbricating  concentric  lines  of  growth,  showing  more  promi- 
nently in  front  than  in  upper  portion  of  shell.  Of  the  plications,  the  lateral 
ones  do  not  reach  to  the  beak,  but  run  out  on  the  margins  of  the  cardinal 
area. 

The  dimensions  of  this  species  are  as  follows :  it  measures  from  one-half  to 
three-fourths  of  an  inch  in  length,  and  from  three-fourths  to  seven-eighths  of 
an  inch  in  width  ;  its  width  always  exceeds  its  length. 

This  species  takes  an  intermediate  position  between  Spir.  gregaria  and  Spir. 
varicosa  ;  it  is  more  transverse  than  the  former,  and  less  so  than  the  latter  ;  its 
umbo  is  less  elevated  and  curved  than  that  of  gregaria,  and  more  so  than  that 
of  varicosa ;  its  deeper  and  sharply  angular  sinus,  and  its  more  elevated  fold, 
distinguish  it  from  both  of  its  relations.  It  is  a  well  marked  and  easily 
recognized  species. 

Formation  and  Locality. — Found  in  the  upper  strata  of  the  Devonian  limestone  around  the  Falls 
of  the  Ohio,  in  Kentucky  and  Indiana.  Very  fine  specimens  I  found  in  considerable  numbers  in  the 
quarries  at  Lexington,  Indiana.  I  dedicate  this  species  to  Dr.  K.  M.  Byrnes,  of  Cincinnati,  Ohio,  who 
devotes  all  his  spare  time  to  the  study  of  geology  and  palaeontology,  and  who  greatly  contributed  to  our 
knowledge  of  the  Cincinnati  fossil  fauna. 


110  PALEONTOLOGY    OF    KENTUCKY. 


Spirifera  conradana.    s.  A. 

Plate  VII.,  figures  11,  12  and  13. 

Delthyris  fimbriata,  Conrad.     Jour.  Acad.  Nat.  Science,  Philadelphia,  Vol.  VIII.,  p.  263—1842. 
Spirifera  fimbriata,  Conrad.     Billings  in  Canadian  Jour.,  p.  259  —  1861. 
Spirifera  fimbriata,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  214,  pi.  33. 

Shell  transversely  sub-elliptical,  gibbous;  hinge-line  less  than  width  of 
shell  ;  cardinal  extremities  rounded. 

Ventral  valve  gibbous  in  upper  half,  regularly  curving  to  front  and  sides  ; 
sinus  well  denned,  usually  shallow^  and  rounded,  sometimes  deep  and  angular, 
and  much  produced  in  front.  Beak  small  and  incurved  over  the  area,  which 
is  high  and  concave,  and  extending  about  half  the  entire  width  of  the  shell  ; 
foramen  often  limited  by  a  sharp  elevated  border,  which  appears  to  be  a  pro- 
jection of  the  dental  plates. 

Dorsal  valve  gibbous,  regularly  convex  on  the  sides,  a  little  flattened  at  the 
cardinal  extremities  ;  mesial  fold  abruptly  elevated  in  the  lower  part,  often  but 
little  elevated  or  scarcely  denned  in  the  upper  part  ;  beak  small,  slightly 
arched  over  the  sub-linear  area,  which  is  somewhat  concave. 

Surface  marked  by  from  three  to  nine  low,  rounded,  often  obscure  plications 
on  each  side  of  the  mesial  fold  and  sinus  ;  these  are  crossed  by  imbricating, 
lamellose  striae,  which  are  sometimes  wide  or  distant,  and  often  crowded. 
The  concentric  striae  are  studded  with  elongated  nodes  or  tubercles,  which  are 
thus  arranged  in  parallel  bands,  more  or  less  contiguous,  according  to  distance 
of  the  concentric  striae. 

The  elongate  tubercles  may,  perhaps,  more  properly  be  regarded  as  inter- 
rupted radiating  striae,  which,  in  the  perfect  condition  of  the  shell,  have, 
doubtless,  extended  in  slender  spines  or  setae  ;  they  are  termed  by  Mr.  Conrad 
short  longitudinal  striae. 

The  cardinal  area  is  strongly  striated  vertically.  This  species  begins  its 
existence,  so  far  as  we  know,  in  the  Oriskany  sandstone,  where  it  has  been  so 
rarely  observed.  It  occurs  in  the  Schoharie  grit,  and  reaches  its  greatest 
dimensions  in  the  Corniferous  limestone,  where  it  not  seldom  attains  a  width 
of  nearly  two  inches  by  a  length  of  an  inch  and  a  quarter.  It  is  often  found 
well  preserved  in  the  Hamilton  formation,  but  does  not  here  attain  the  size 
it  has  in  the  Corniferous  limestone.  (Hall.) 

The  Sp.  conradana  is  not  found  in  strata  younger  than  the  Hamilton,  but 
it  is  represented  in  later  periods  by  forms  showing  great  similarity  to  it. 

Formation  and  Locality.  —  Under  this  heading  I  give  only  the  places  and  groups  in  which  the 
species  in  question  is  found  in  Kentucky.  Sp.  conradana  is  found  in  the  Devonian  limestone  of  Kentucky 
and  Indiana,  near  and  at  the  Falls  of  the  Ohio,  but  is  not  abundant  This  species  has  been  known 
ever  since  Mr.  Conrad's  first  description  of  the  same  as  Spir.  fimbriata,  but  it  can  not  retain  its  specific 
designation,  inasmuch  as  Mr.  Morton  pro-occupied  the  name  Spir.  fimbriata,  in  1836,  for  a  different  Spiri- 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  Ill 

fer  of  the  Coal  Measures.  Conrad's  first  description  of  this  species  and  its  naming  date  only  back  to  1842. 
Mr.  Morton's  right  to  the  name  can  not  be  disputed;  Mr.  Conrad's  species  must,  therefore,  be  dropped. 
Mr.  Miller  has  proposed  the  name  "  Conradana  "  as  a  substitute,  which  I  hereby  cheerfully  accept.  Mr. 
Miller  named  the  species  in  honor  of  Mr.  Conrad,  former  geologist  of  the  State  of  New  York. 

Spirifera  crispa,  var.  simplex.    HALL. 

Plate  XVII.,  figures  36  and  37. 
Spirifera  crispa,  var.  simplex,  Hall,     llth  Eep.  of  Ind. — 1881. 

Shell  small,  semi-circular  or  semi-elliptical,  more  or  less  gibbous  or  ventri- 
cose;  both  valves  about  equally  convex ;  hinge-line  somewhat  less  than  the 
greatest  width  of  the  shell ;  cardinal  extremities  obtuse  or  rounded.  Surface 
plicate. 

Central  valve  ventricose,  with  its  greatest  convexity  about  the  middle  of 
the  valve,  from  where  it  curves  regularly  towards  the  anterior  and  lateral 
margins ;  mesial  sinus  well  defined  from  apex  to  front,  deep  and  angular  in 
the  bottom,  and  widening  towards  the  front,  where  it  forms  a  strong  triangular 
projection ;  cardinal  area  high,  but  not  defined  in  its  margins,  which  are 
rounded,  and  gradually  extend  into  the  surface  of  the  valve  ;  foramen  or  fis- 
sure long  and  narrow ;  beak  arched,  but  not  incurved. 

Dorsal  valve  nearly  as  ventricose  as  the  other,  having  its  greatest  convexity 
about  the  middle  of  the  valve,  from  where  it  curves  regularly  towards  front 
and  sides.  Mesial  fold  well  defined,  strong  and  angular  ;  beak  small  and  curv- 
ing over  a  linear  area. 

Surface  marked  on  each  side  of  mesial  depression  and  elevation  by  two  or 
three  plications,  of  which  only  the  first  one  near  fold  or  sinus  is  mostly  strong 
and  well  marked,  while  the  others  are  either  only  slightly  elevated  or  some- 
times entirely  obsolete.  The  whole  surface  of  the  shell  is  covered  by  strong, 
thread-like  concentric  striae. 

These  specimens  are  considerably  smaller  than  those  used  by  Professor  Hall 
for  his  figures  and  description  in  the  Indiana  Report,  which  came  from  Wal- 
dron,  Indiana.  Even  some  slight  differences  exist  between  our  Kentucky 
shells  and  those  from  Indiana,  but  these  differences  do  not  justify  a  further 
specific  separation. 

Formation  and.  Locality. — Occurs  in  the  upper  strata  of  the  Niagara  formation,  in  the  quarries 
east  of  the  city  of  Louisville,  Ky.,  where  it  is  somewhat  abundant,  but  well  preserved  specimens  are  rather 
rare. 


112  PALEONTOLOGY    OF    KENTUCKY. 

Spirifera  davisi.    N.  sr. 

Plate  XII.,  figures  1,  2,  3  and  4. 

This  shell  was  given  to  me  by  one  of  the  collectors  around  the  Falls  of  the 
Ohio  as  a  Spirifera  raricosta,  with  which  it  has  some  similarity,  but  from  which 
it  is  easily  distinguished  by  its  form  and  surface-markings. 

The  shell  is  semi-circular  or  sub-quadrate  and  gibbous.  Hinge-line  equal  or 
larger  than  the  greatest  width  of  the  shell.  Cardinal  extremities  acute  and 
mostly  somewhat  acuminate.  Surface  strongly  plicated. 

Ventral  valve  considerably  more  gibbous  than  dorsal  valve,  regularly  arcuate 
from  beak  to  front ;  greatest  convexity  at  or  a  little  above  middle,  and  curving 
gently  to  the  sides  and  front,  except  at  the  cardinal  angles,  which  are  some- 
what flattened ;  beak  much  elevated  above  that  of  the  opposite  valve,  and 
arching  over  that  fissure,  but  scarcely  incurved.  Cardinal  area  high  and  con- 
cave, and  reaching  to  the  cardinal  extremities.  Mesial  sinus  is  broad  and 
rounded  and  reaches  quite  to  the  apex.  Dorsal  valve  gibbous,  most  convex  in 
the  middle,  flattened  or  a  little  concave  towards  the  cardinal  extremities.  The 
mesial  fold  is  very  prominent,  rounded,  and  regularly  arcuate  ;  it  has  a  faint 
impression  extending  from  beak  to  middle  of  valve. 

The  beak  is  small  and  arched  over  the  linear  area.  Surface  is  marked  by  six 
to  eight  rounded  or  sub-angular  plications  on  each  side  of  the  mesial  fold  and 
sinus.  The  shell  is  smooth,  with  the  exception  of  front  part,  which  is  marked 
by  from  live  to  seven  strong  concentric  imbricating  lines  of  growth,  which 
reach  to  the  cardinal  angles,  and  which  give  to  the  shell  its  peculiar  beautiful 
front  view.  Such  imbricated  front  is  only  noticed  in  Spir.  gregaria  and  in 
Spir.  mucronata,  in  both  of  which  it  is  less  regular  and  less  prominent.  Inte- 
rior of  shell  is  unknown.  The  specimens  so  far  found  show  a  great  similarity 
in  form  and  also  in  size  ;  they  measure  from  one  inch  to  one  inch  and  a  quarter 
in  width,  by  from  three-fourths  to  seven- eighths  of  an  inch  in  length.  This 
species  is  related  to  Spir.  raricosta  and  to  Spir.  gregaria.  From  the  former  it 
differs  in  its  greater  number  of  plications;  its  somewhat  acuminate  cardinal 
extremities ;  its  larger  and  more  elevated  hinge-area,  and  by  its  peculiar 
imbricated  front.  From  Spir.  gregaria  it  is  distinguished  by  its  larger  size, 
by  its  smooth  shell,  by  its  greater  width,  and  by  its  less  prominent  umbo, 
and  also  by  its  more  marked  imbricated  front. 

Formation  and  Locality. — Spirifera  davisi  is  found  associated  with  Spir.  gregaria  in  the  upper 
strata  of  the  Devonian  limestone  in  Kentucky  and  Indiana,  in  the  neighborhood  of  the  Falls  of  the  Ohio; 
it  is  not  abundant,  and  only  found  in  a  few  limited  localities,  where  it  occurs  in  well  preserved  specimens 
I  have  named  this  species  in  honor  of  my  friend  and  co-laborer,  W.  I.  Davis,  the  author  of  "  Kentucky 
Fossil  Corals,"  who  devoted  his  attention  and  study  mostly  to  the  fossil  corals,  in  which  the  Falls  of  the 
Ohio  and  its  surrounding  quarries  are  so  exceedingly  rich. 


FOSSILS    OF    THE    SILUEIAN    AND    DEVONIAN    BOOKS.  113 

Spirifera  divaricata.    HALL. 

Plate  XI.,  figures  6  to  11,  and  Plate  XII.,  figures  5  to  11.' 
Spirifer  divaricatus,  Hall.     Tenth  Rep.  on  the  State  Cab.,  p.  130 — 1857. 
Spirifer  venstus,  Hall.     Thirteenth  Rep.  on  State  Cabinet,  p.  82 — 1860. 
Spirifera  divaricata,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  213,  plate  32. 

Shell  ventricose,  somewhat  rhomboidal  or  quadrilateral  (looking  upon  the 
ventral  valve).  Dorsal  valve  semi-elliptical ;  hinge-line  less  than  width  of  the 
shell ;  cardinal  extremities  obtuse  or  rounded  ;  area  large. 

Ventral  valve  most  convex  above  the  middle,  extremely  arcuate  from  umbo 
to  base  ;  abruptly  curving  to  the  sides  ;  beak  abruptly  arching  over  the  area  ; 
sinus  plicated,  shallow  above  and  becoming  rapidly  expanded  below,  with  the 
margin  undefined  and  terminating  in  a  broad,  triangular  extension  in  front. 
Area  high,  flat  below,  but  abruptly  arcuate  above,  and  reaching  to  the  cardinal 
extremities  ;  foramen  large. 

Dorsal  valve  regularly  and  strongly  convex,  with  an  angular  mesial  fold, 
which  is  narrow  above  and  expands  towards  the  front,  with  bifurcating  plica- 
tions ;  sides  regularly  curving  and  sometimes  a  little  flattened  towards  the 
cardinal  extremities.  Area  rather  wide,  with  the  beak  and  central  portion  of 
the  valve  arching  over  it.  The  surface  is  marked  by  numerous  fine  bifurcating 
rounded  or  sub-angular  plications  ;  mesial  sinus  having  on  each  side  a  stronger 
plication,  which  bifurcates  on  one  or  both  sides.  At  the  beak  there  is  a  single 
plication  in  the  bottom  of  the  sinus,  which  sometimes  continues  simple  nearly 
or  quite  to  the  base ;  while  the  accessions  take  place  mainly  from  those  on  the 
sides  of  the  depression,  till  they  reach  the  number  of  ten,  eleven  or  twelve 
within  the  limits  of  the  sinus  near  the  base.  In  a  specimen  of  ordinary  size, 
where  the  surface  is  well  preserved,  there  are,  sometimes,  sixty  and  more  plica- 
tions with  their  divisions  at  the  margin  of  the  shell.  In  some  specimens  from 
the  Corniferous  limestone,  where  the  surface  is  partially  or  entirely  exfoliated, 
the  bifurcating  character  of  the  striae  is  not  observed,  and  in  some  specimens 
the  plications  appear  to  have  been  simple  throughout.  The  plications  are 
crossed  by  fine  imbricating  lamellose  striae,  which  are  abruptly  arched  back- 
wards. (Plate  12,  figure  11.)  A  cast  of  the  ventral  valve  shows  a  large  oval 
muscular  area,  which  is  deeply  divided  by  a  rounded  median  crest,  and 
strongly  striated  on  the  lateral  portion.  (Hall.) 

The  shells  represented  on  plate  12,  figures  5  to  11,  I  was,  at  first,  inclined  to 
consider  as  specifically  different  from  Sp.  divaricata.  They  appeared  more 
robust,  and  their  plications  were  fewer  and  stronger.  Instead  of  a  simple 
bifurcation,  as  in  divaricata,  these  specimens  show  some  instances  where  a 
single  plication  divided  towards  the  base  into  three  and  even  four  branches, 
forming  a  kind  of  fascicle,  which  are  so  characteristic  in  Spirifera  camerata  of 

GKOL.    SUR. — 15 


114  PALAEONTOLOGY    OF    KENTUCKY. 

the  Coal  Measures.  The  true  character  of  the  plications  of  these  shells  is  not 
shown  exactly  in  the  drawings. 

This  shell,  when  well  preserved,  is  one  of  the  finest  Spirifera  of  our  palaeo- 
zoic fauna  ;  it  is  easily  distinguished  from  the  others  by  its  form,  by  its  bifur- 
cating plications,  and  by  its  sharp  zigzag,  concentric  striae. 

Its  size  differs  from  two  to  three  inches  in  width,  and  from  one  and  three- 
fourths  to  two  inches  in  length,  by  a  depth  of  one  inch  and  one-eighth. 

Formation  and  Locality. — Found  in  the  Hamilton  group  and  in  the  Corniferous  limestone  of  Ken- 
tucky, around  Louisville,  and  near  Lebanon,  Kentucky,  where  W.  T.  Knott,  Esq.,  found  some  very  fine 
specimens,  which  are  figured  on  plate  11.  This  species  is  not  very  rare,  though  it  is  very  difficult  to  pro- 
cure good  specimens. 

Spirifera  duodenaria.    HALL. 

Plate  XII.,  figures  12,  13  and  16.      - 

Delthyris  duodenaria,  Hall.     Geol.  Rep.  4th  Dist.  N.  Y.,  p.  171,  figure  5 — 1843. 
Spirifer  duodenaria,  Hall.     Catalogue  in  Rep.  on  State  Cabinet. 
Spirifera  duodenaria,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  189,  pi.  27  and  28. 

Shell  transverse,  semi-circular ;  hinge-line  equal  to  greatest  width  of  shell ; 
cardinal  extremities  obtuse  or  acute,  rarely  acuminate  ;  valves  sub-equally  con- 
vex ;  area  very  narrow.  .  Surface  plicated. 

Ventral  valve  moderately  gibbous ;  arcuate,  compressed  towards  the  cardinal 
extremities.  Mesial  sinus  of  moderate  width  and  depth ;  rounded  or  slightly 
flattened  on  the  bottom;  umbo  prominent;  beak  small,  neatly  curved  over  a 
wide  triangular  fissure,  and  reaching  to  within  half  a  line  of  the  umbo  of  the 
opposite  valve  ;  area  concave,  sub- linear,  a  little  wider  on  each  side  near  the 
center. 

Dorsal  valve  regularly  convex,  a  little  gibbous  in  the  middle  and  flattened 
or  sometimes  slightly  concave  at  the  cardinal  extremities.  Mesial  fold  rather 
narrow,  rounded,  prominent  and  strongly  defined,  sometimes  a  little  flattened 
on  the  middle.  The  surface  is  marked  by  six  and  rarely  seven  strongly 
rounded  ribs  on  each  side  of  the  mesial  fold  or  sinus.  The  ribs  gradually 
decrease  in  size  and  prominence  from  the  center ;  and  the  outer  ones  are  often 
scarcely  elevated  in  young  or  medium- sized  individuals.  The  entire  surface  is 
marked  by  lamellose,  concentric  striae,  giving  a  papillose  or  sub-fimbriate 
aspect  at  their  junction ;  it  usually  happens,  however,  that  the  surface  is 
smooth  from  partial  exfoliation.  (Hall.) 

This  species  has  usually  a  width  of  one  inch  to  one  inch  and  a  quarter,  and  a 
length  of  one-half  to  three-fourths  of  an  inch.  Younger  individuals,  such  as 
are  figured  on  plate  12,  are  smaller  in  size,  and  generally  contain  less  plications. 

Formation  and  Locality. — This  species  is  found  in  the  Corniferous  limestone  of  Kentucky  and 
Indiana,  around  the  Falls  of  the  Ohio,  but  is  very  rare.  During  ten  years  of  collecting  I  have  found  only 
two  or  three  specimens,  and  these  not  even  in  very  good  condition, 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  115 

Spirifera  dubia.    N.BP. 

Plate  XXXIII.,  figures  23  and  24. 

This  shell  I  found  in  the  strippings  of  a  quarry  east  of  the  city  of  Louis- 
ville, where  the  top  rocks  belong  to  the  Devonian,  and  the  lower  strata  to  the 
Silurian ;  it  is.  therefore,  impossible  to  state  to  which  of  these  formations  it 
belongs.  It  further  has  in  form  and  outline  great  similarity  with  Spir.  crispa, 
var.  simplex,  from  which  it,  however,  differs  greatly  in  other  points.  Concern- 
ing this  shell  there  is,  therefore,  doubt  in  regard  to  its  formation,  and  also 
whether  or  not  it  should  form  a  new  species,  and  for  these  reasons  I  think  it 
fully  deserves  its  specific  name. 

Shell  small,  semi-circular  or  semi  elliptical  and  ventricose.  Convexity  of 
both  valves  almost  equal ;  hinge  line  less  than  greatest  width  of  shell ;  cardinal 
extremities  rounded.  Surface  without  plications. 

Ventral  valve  ventricose,  having  its  greatest  convexity  a  little  above  the 
middle  of  the  shell,  from  where  it  curves  regularly  and  markedly  to  the 
anterior  and  lateral  margins.  Mesial  sinus  extends  from  beak  to  front,  shallow 
in  the  upper  part,  deepening  and  widening  towards  the  base ;  angular  in  the 
bottom,  but  its  margins  not  at  all  defined ;  in  front  it  forms  a  pretty  strong 
triangular  extension.  Cardinal  area  elevated,  with  undefined  rounded  mar- 
gins ;  beak  arcuate,  but.  not  incurved  over  a  high  and  narrow  fissure. 

Dorsal  valve  almost  as  convex  as  the  other,  having  its  greatest  convexity  a 
little  above  the  middle,  from  where  it  curves  regularly  towards  the  front  and 
sides.  Mesial  fold  not  at  all  noticeable  on  the  umbo ;  little  elevated  and  sub- 
angular  towards  the  base  ;  beak  incurved  over  a  narrow  area. 

Surface  having  not  the  least  trace  of  plications,  but  covered  by  lamellose, 
imbricating,  concentric  striae,  similar  to  those  in  Spir.  var.  simplex.  Size  of 
shell  is  three-eighths  of  an  inch  in  length,  and  a  little  less  than  one-half  of  an 
inch  in  width. 

Formation  and  Locality. — The  formation  from  which  it  comes  uncertain  as  above  stated ;  found  in 
a  quarry  east  of  the  city  of  Louisville.  This  one  specimen  the  only  one  so  far  known, 

Spirifera  euruteines.    OWEN. 

Plate  VI.,  figures  1  to  7;  9,  11  to  17. 

Delthyris  (Spirifer)  euruteines,  Owen.     Report  of  Geological  Exploration  in  Iowa,  Wisconsin  and  Illinois. 
Spirifer  euruteines,  Owen.     Geol.  Surv.  of  Wise.,  Iowa  and  Minn.,  p.  586,  Tab.  III.,  figs.  2  and  2a,  and 

6,  6a,  b. 
Spirifera  euruteines,  Hall.     Pal.  of  N.  Y.,  Vol.  IV.,  page  209,  plate  31,  figures  14  to  19. 

This  species  was  first  described  and  figured  by  Prof.  David  Dale  Owen,  in 
his  report  on  the  Geological  Survey  of  Wisconsin,  Iowa  and  Minnesota,  from 
specimens  found  on  Pine  creek,  Iowa.  Owen  states  that  this  is  the  same  shell 


116  PALEONTOLOGY    OF    KENTUCKY. 

found  in  great  abundance  in  the  hydraulic  limestone  at  the  Falls  of  the  Ohio, 
near  Louisville.  The  figures  given  by  him  in  said  report  can  not  belong  to  one 
and  the  same  species  ;  those  marked  2  and  2a  are  by  far  too  large  and  robust ; 
the  cardinal  view  in  figure  2  measures,  between  the  cardinal  extremities,  two 
and  one-fourth  inches,  while  the  breadth  of  euruteines  was  given  by  Owen  to  be 
one  and  a  half  inches.  The  figures  6,  6<z,  6&,  must  be  taken  as  the  correct 
representation  of  Owen's  Sp.  euruteines. 

Prof.  Hall  described  in  Pal.  N.  Y.,  volume  4,  pages  209,  210  and  211,  Sp. 
euruteines  and  Sp.  euruteines,  var.  fornacula ;  the  difference  of  these  consists 
only  in  the  greater  curvature  of  the  cardinal  area  in  fornacula.  Owen's  side 
view  of  euruteines  shows  the  cardinal  area  considerably  concave  ;  the  curvature 
equal  through  the  whole  area  from  hinge-line  to  the  apex  of  the  beak  ;  while 
Hall's  side  view  of  euruteines  marks  the  cardinal  area  as  straight,  with  the 
exception  of  a  little  offset  near  the  beak.  Among  Hall's  figures  no  side  view 
is  given  of  fornacula ;  we  are,  therefore,  left  uncertain  as  to  the  amount  of  cur- 
vature required  to  place  a  euruteines  among  the  var.  fornacula.  The  hinge- area 
in  this  species  is  exceedingly  variable;  in  some  it  is  straight,  and  leans  forward, 
in  others  it  is  also  straight,  but  leans  backward  ;  then,  again,  it  leans  forward 
but  is  curved  a  little  near  the  beak,  while  in  others  it  leans  backward  and  is 
bent  either  only  near  the  beak  or  throughout  its  entire  height.  Spirifera 
euruteines  is  described  by  Prof.  Hall  in  Pal.  N.  Y.,  volume  4,  page  209,  as 
follows : 

Shell  semi-elliptical ;  length  and  breadth  about  as  six  to  ten  ;  hinge-line 
equal  to  greatest  width  of  shell.  Surface  plicate. 

Ventral  valve  sub -pyramidal,  the  elevation  being  nearly  equal  to  half  the 
width,  curving  abruptly  and  equally  to  the  front  and  lateral  margins  ;  the 
distance  from  the  apex  to  the  cardinal  extremity,  and  to  the  front  of  the  shell, 
being  about  equal.  Apex  sometimes  projecting  slightly  over  the  area ;  mesial 
sinus  shallow,  well  defined,  and  reaching  to  the  apex ;  sometimes  a  little 
flattened  in  the  bottom.  Area  extremely  elevated,  nearly  flat  or  slightly 
concave  above ;  fissure  large  and  open  to  the  apex,  the  length  of  its  sides  being 
about  once  and  a  half  the  width  of  its  base. 

Dorsal  valve  moderately  and  evenly  convex,  with  a  well  defined,  low  rounded 
mesial  fold  ;  beak  and  margin  of  the  valve  in  the  middle  slightly  arched  ;  area 
narrow  at  the  sides,  but  having  the  width  of  a  line  in  the  middle.  Surface 
marked  by  from  16  to  20  plications  on  each  side  of  the  mesial  fold  or  sinus  ; 
these  plications  are  rounded  and  well  defined ;  about  eight  of  them  reach  the 
apex  on  the  ventral  valve,  and  the  remainder  coalesce  with  the  angular  border 
of  the  area.  In  perfect  specimens,  the  entire  surface  has  been  covered  by  fine 
concentric  undulating  striae,  which  are  crossed  by  fine  radiating  striae ;  the 
remains  of  these  on  some  of  the  silicified  specimens  give  a  granulose  surface. 


FOSSILS    OF    TEtF,    SILURIAN    AND     DEVONIAN    ROCKS.  117 

The  length  of  a  full  grown  individual  is  a  little  more  than  three-fourths  of 
an  inch,  its  width  about  one  inch  and  three- eighths,  and  its  height  also  about 
three-fourths  of  an  inch.  (Hall.) 

After  the  foregoing  description  Prof.  Hall  makes  the  following  statement : 
"I  have  before  me  more  than  a  dozen  specimens  from  near  the  Falls  of 
the  Ohio,  or  from  Charlestown  Landing,  among  which  there  is  very  little  varia- 
tion in  the  general  features." 

If  those  specimens  did  not  show  great  variations,  they  must  have  formed  a 
picked  lot.  I  have  before  me  more  than  an  hundred  shells  of  this  species, 
which  I  could  easily  divide  into  at  least  live  different  groups.  The  extreme 
form  of  each  group  is  so  pronounced  in  its  features,  and  so  greatly  different 
from  the  extreme  form  of  other  groups,  that  they,  by  themselves,  would  con- 
stitute good  species ;  but  the  intermediate  forms  connect  all  these  groups  to 
one  single  species. 

Formation  and  Locality. — Found  in  great  abundance,  and  well  preserved,  in  the  Devonian  limestone 
in  Kentucky  and  Indiana,  near  and  at  the  Falls  of  the  Ohio.  Some  of  the  specimens  have  preserved  the 
internal  spiral  coils  in  almost  perfect  condition,  as  may  be  seen  by  plate  6,  figures  21  and  22. 

Spirifera  euruteines,  var.  fornacula.    HALL. 

Plate  VI.,  figures  8,  10,  18,  19  and  20. 
Spirifera.  euruteines,  var.  jornacula,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  page  211,  pi.  31,  figures  11,  12  and  13. 

Prof.  Hall,  in  describing  this  variety,  remarks  that  it  possesses  the  essential 
characters  of  Spir.  euruteines,  and  points  out,  as  the  only  difference  from  that 
species,  that  its  area  is  a  little  more  arcuate  in  the  upper  part.  Those  figured 
by  "me  here  are  of  the  type  which  is  generally  considered  as  fornacula  by  all 
the  geologists  living  in  the  cities  around  the  Falls  of  the  Ohio.  The  strong 
curvature  of  the  whole  cardinal  area  is  their  only  marked  characteristic. 

Formation  and  |  Locality.— Associated  with  the  preceding  species  in  the  Devonian  limestone  in 
Kentucky  and  Indiana,  around  the  Falls  of  the  Ohio. 

Spirifera  foggi     N.BP. 

Plate  XXXII.,  figures  28,  29,  30  and  31. 

Shell  of  medium  size ;  sub-circular  sub-oval  or  sub-elliptical ;  very  ventn- 
cose  or  gibbous ;  hinge-line  greatly  less  than  width  of  shell ;  cardinal  extremi- 
ties rounded.  Surface  plicated. 

Ventral  valve  ventricose  in  young  specimens,  becoming  gibbous  in  old  ones  ; 
greatest  convexity  a  little  above  the  middle  of  the  valve,  from  where  it  slopes 
in  a  gentle  regular  curve  to  the  front,  but  abruptly  to  the  cardino-lateral  mar- 
gins ;  a  mesial  sinus  extends  from  beak  to  front,  well  defined  in  its  whole 


118  PALAEONTOLOGY    OP    KENTUCKY. 

course,  moderately  widening,  but  not,  or  very  little,  increasing  in  depth  towards 
the  front ;  flat  at  the  bottom,  and  having  only  a  small  basal  extension,  which 
is  not  deflected ;  umbo  more  or  less  prominent,  according  to  age,  and  beak 
strongly  arched  over  the  umbo  of  opposite  valve ;  hinge -area  small  and  unde- 
fined in  its  margins,  which  are  rounded  and  coalesce  with  the  surface  of  the 
valve  ;  triangular  fissure  of  moderate  size,  with  its  base  to  its  height  as  two  to 
three. 

Dorsal  valve  of  equal  convexity  with  the  ventral,  both  in  young  and  old 
shells  :  greatest  convexity  below  the  umbo,  from  where  it  slopes  very  abruptly 
to  the  cardinal  margin,  but  in  a  gentle  and  regular  curve  to  the  lateral  and 
basal  margins  ;  a  mesial  fold  of  moderate  elevation  and  moderate  width,  but 
well  defined  in  its  whole  course,  extends  from  beak  to  front,  with  a  flat  or 
broadly  rounded  summit ;  umbo  moderate,  and  beak  strongly  incurved  into 
the  foramen  of  the  opposite  valve.  Surface  ornamented  by  five  to  six  broadly 
rounded  plications  on  each  side  of  the  mesial  fold  or  sinus,  of  which  only 
the  first  one,  adjacent  to  the  median  elevation  or  depression,  is  of  moderate 
size  and  plainly  marked  from  beak  to  front,  while  the  others  diminish  in  size 
and  distinctness  more  and  more  toward  the  lateral  margins.  In  well  preserved 
specimens  retaining  the  shell,  the  surface  is  covered  with  fine,  thread-like, 
radiating  striae,  which  increase  greatly  towards  the  front  by  bifurcation  ;  these 
striae  are  crossed  by  fine  imbricating  lines  of  growth,  which  become  somewhat 
crowded  near  the  front.  This  species  is  generally  found  as  exfoliated  casts, 
which  do  not  show  these  radiating  and  concentric  lines,  or  at  least  indicate 
them  only  very  faintly. 

Professor  Hall  has  repeatedly,  but  always  with  the  expression  of  doubt, 
referred  this  species  to  Spirifera  niagarensis,  but  it  appears  to  me  that  it  differs 
too  much  from  that  shell  to  be  associated  with  it.  Spir.  niagarensis  shows 
in  all  of  HalFs  figures  large  cardinal  dimensions  ;  it  has  a  hinge- line  as  large 
as  the  width  of  the  shell ;  it  also  has  a  considerable  hinge-area,  which  is  well 
defined,  and  its  plications  are  numerous  and  plainly  marked ;  all  these  points 
are  greatly  different  in  our  shell ;  its  hinge-line  is  very  short,  not  exceeding 
one-half  the  width  of  the  shell ;  the  cardinal  area  is  small,  and  not  defined  by 
sharp,  angular,  but  by  broadly  rounded  margins,  and  the  plications  are  few, 
and  only  faintly  marked.  These  differences  are  certainly  sufficient  to  separate 
our  shell  specifically  from  Spir.  niagarensis.  Nearer  related  is  this  species  to 
Spirifera  radiata,  from  which  it  differs  only  by  its  small  cardinal  area,  which, 
however,  occurs  in  some  specimens  of  that  species  also,  but  mainly  by  its 
plicated  surface.  It  certainly  occupies  an  intermediate  position  between  Spir. 
niagarensis  and  Spir.  radiata,  of  which  it  presents  the  transition-form  in  the 
process  of  evolution. 

Formation  and  Locality — Tt  occurs  in  the  Niagara  group  so  prominently  exposed  in  the  quarries 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  119 

east  of  the  city  of  Louisville,  where  it  is  rare,  generally,  but  more  so  in  well  preserved  individuals;  only 
a  few  specimens  of  this  species  are  to  be  found  in  the  different  cabinets  of  the  Falls  Cities.  It  affords  me 
great  pleasure  to  name  this  species  in  honor  of  my  friend,  the  noble-hearted  and  venerable  Mr.  Fogg,  of 
Jeffersonville,  Indiana. 

Spirifera  gregaria.    CLAPP. 

Plate  VIII.,  figures  9  to  13,  and  Plate  X.,  figures  6  to  10. 

Spirifer  gregaria,  Clapp.     MS. 

Spirifer  gregaria,  Hall.     Tenth  Kep.  on  the  State  Cab.,  p.  127 — 1857. 
Spirifer  gregaria,  Clapp.     Billings  in  Canadian  Jour.,  p.  128 — 1857. 
Spirifera  gregaria.  Hall.     Pal.  N.  Y.,  Vol.  4,  p.  195,  plate  28. 

Shell  ventricose,  sub-globose,  semi-oval  or  sub-quadrate  in  outline ;  hinge- 
line  usually  equal,  but  sometimes  less  than  width  of  shell ;  cardinal  extremities 
truncate  or  somewhat  rounded.  Surface  plicated. 

Ventral  valve  very  gibbous,  and  more  so  than  the  dorsal  valve ;  it  is  regularly 
arcuate  from  beak  to  front.  Its  greatest  convexity  is  at  or  a  little  above  the 
middle,  from  where  it  curves  somewhat  abruptly  to  the  sides,  but  more  gently 
to  the  front ;  beak  much  elevated,  and  apex  closely  incurved  over  the 
fissure;  area  high,  concave  and  extending  to  the  cardinal  angles,  where  it  is 
sometimes  more  than  half  a  line  high,  often  distinctly  striated ;  mesial  sinus 
rounded  or  sub-angular  and  much  produced  in  front. 

Dorsal  valve  very  convex  with  a  strong  mesial  fold,  either  angular  or  some- 
what flattened  along  the  summit,  and  sometimes  marked  by  an  indistinct 
groove ;  beak  often  considerably  elevated,  and  slightly  inclined  over  the 
hinge  area,  which  is  narrow  except  in  the  center,  where  it  widens  perceptibly 
Surface  marked  by  from  six  to  ten  strong  rounded  ribs  on  each  side  of  the 
mesial  fold  and  sinus.  The  entire  surface  is  covered  with  undulating  con- 
centric striae,  which,  towards  the  front,  become  strong  zigzag  imbricating 
lines  of  growth,  resembling  somewhat  the  front  ornamentation  of  Spirifera 
davisi. 

The  interior  of  the  ventral  valve  presents  a  well  defined,  oval,  muscular 
impression,  with  a  low  crest  in  the  center.  The  dental  plates  are  often  much 
thickened,  filling  the  entire  rostral  cavity,  and  encroaching  upon  the  muscular 
area. 

The  width  of  this  species  ranges  from  one-half  to  seven-eighths  of  an  inch, 
and  the  length  is  usually  a  little  less  than  the  width;  but  there  are  some  speci- 
mens in  which  the  length  equals  or  even  exceeds  a  little  the  width,  as  may 
be  seen  in  the  one  figured  on  plate  8.  In  very  gibbous  specimens  the  beak 
of  the  ventral  valve  is  so  extremely  elevated,  that  almost  one-half  of  the  ven- 
tral valve  is  above  the  cardinal  line.  In  the  majority  of  specimens  there  are 
six  or  seven  plications  on  each  side  of  the  mesial  fold  or  sinus.  The  variable 


120  PALEONTOLOGY    OF    KENTUCKY. 

gibbosity  of  the  shell  gives  an  apparent  variation  in  the  height  of  the  area ; 
the  beaks  of  the  two  valves  sometimes  approach  very  close  to  each  other. 
(Hall.) 

Formation  and  Locality. — This  species  is  found  abundantly  in  the  Corniferous  limestone  at  and 
around  the  Palls  of  the  Ohio  in  Kentucky  and  Indiana.  It  appears  here  silicified,  in  well  preserved 
specimens  of  the  whole  shell,  as  well  as  of  the  separated  single  valves.  Specimens  still  inclosed  in  the 
limestone  are  of  the  same  material.  From  observations  made  by  me  at  the  Falls  of  the  Ohio,  and  which, 
undoubtedly,  were  also  made  by  other  geologists,  who  visited  and  examined  that  world-renowned  store- 
house of  Devonian  fossils,  but  of  which  I  never  found  any  notice  in  print,  I  am  forced  to  the  conclusion 
that  the  silicification  of  the  shells  and  corals  is  produced  by  their  exposure  to  water  and  weather,  and  that 
this  process  requires  only  a  comparatively  short  time.  Whenever,  at  low  stages  of  the  water,  the  bed  of 
the  falls  becomes  dry,  we  find  it  entirely  covered  by  fossil  shells  and  corals,  partly  exposed  above  the  solid 
rock  and  partly  inclosed  in  the  same.  All  the  exposed  fot>sils  which  have  been  acted  upon  by  water  and 
weather  for  some  length  of  time  are  silicified,  as  far  as  they  are  above  the  matrix,  while  the  inclosed 
parts  are  still  limestone,  or,  if  a  change  in  their  material  has  already  commenced,  the  silicification  has 
not  sufficiently  advanced  to  resist  the  dissolving  power  of  muriatic  acid,  which  has  not  the  least  influ- 
ence upon  the  exposed  parts.  In  the  same  condition  are  the  fossils  found  in  the  fields  near  the  falls 
in  Kentucky  and  Indiana.  Those  which  are  entirely  weathered  out,  and  the  parts  of  others  freed  from 
the  matrix,  are  silicious,  while  the  inclosed  parts  have  retained  their  original  material. 

Spirifera  grieri.    HALL. 

Plate  IX.,  figures  8  to  14. 

Spirifer  grieri,  Hall.     Tenth  Rep.  on  State  Cab.,  p.  127 — 1857. 
Spirifer  grieri,  Hall.     Pal.  N.  Y.,  Vol.  4,  p.  194,  plates  27  and  23. 

Shell  gibbous,  transversely  oval  or  sub- quadrilateral,  sometimes  longitudi- 
nally ovate,  the  proportion  of  length  and  breadth  being  very  variable ;  hinge- 
line  considerably  shorter  than  the  greatest  width  of  the  shell ;  cardinal 
extremities  rounded.  Valves  sub-equally  convex. 

Ventral  valve  gibbous  or  ventricose ;  most  convex  above  the  middle,  and 
nearly  opposite  the  center  of  the  hinge-line,  and  sloping  somewhat  abruptly 
to  the  lateral  margins,  but  more  gently  to  the  front ;  sometimes  regularly 
arched  from  beak  to  front,  and  often  arcuate  in  the  upper  part  and  straight  in 
the  lower  portion.  Umbo  prominent  and  much  elevated  above  the  hinge-line  ; 
beak  more  or  less  incurved  over  the  fissure  of  the  high  and  arcuate  area,  which 
has  a  length  of  one-half  to  nearly  two-thirds  the  width  of  the  shell.  Mesial 
sinus  wide  and  deep,  sub-angular  in  the  lower  portion. 

Dorsal  valve  regularly  arcuate  ;  the  greatest  convexity  near  the  middle,  and 
regularly  curving  to  the  lateral  margin ;  mesial  fold  prominent,  sometimes 
rounded,  but  usually  more  or  less  distinctly  angular ;  beak  small,  slightly 
incurved  over  a  nearly  vertical  narrow  area.  Surface  marked  by  from  six  to 
ten  more  or  less  rounded,  simple  plications  on  each  side  of  the  mesial  fold  or 
sinus,  while  there  are  three  or  four  distinctly  bifurcating  or  dichotomous  plica- 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  121 

tions  upon  the  fold  or  sinus,  giving  six  to  eight  at  the  margin  of  the  shell.  I 
have  before  me  a  specimen  of  grieri,  in  which  the  first  rib  on  each  side  of 
the  mesial  fold  and  the  second  one  on  each  side  of  the  sinus  are  plainly  dicho- 
tomous.  In  perfect  specimens  the  surface  is  covered  by  fine  concentric  lamel- 
lose  striae,  which  are  crossed  by  delicate,  radiating  striae.  This  species  is 
distinguished  from  most  of  the  allied  forms  by  its  simple,  strong  plications 
on  each  side  of  the  mesial  fold  and  sinus,  while  those  occupying  the  latter 
are  smaller  and  bifurcating. 

Sometimes  the  middle  plication  on  the  mesial  fold  is  simple,  in  which  case  the 
fold  is  quite  angular,  while  in  other  instances  it  bifurcates,  leaving  a  longitu- 
dinal depressed  line  on  the  middle,  giving  it  a  more  rounded  outline.  It  is 
only  on  specimens  which  have  suffered  no  injury  by  wearing  or  exfoliation, 
that  the  fimbriate  appearance  of  the  concentric  markings  is  visible.  In  some 
of  the  larger  and  older  individuals  the  plications  are  low  and  gently  rounded, 
in  others  they  are  more  prominent,  while  from  exfoliation  they  often  become 
angular  and  more  conspicuous,  and  the  same  appears  to  be  true  of  the  dicho- 
tomous  plications  of  the  mesial  fold  and  sinus.  The  interior  of  the  shell  is 
so  far  unknown.  (Hall.) 

The  size  of  the  shell  differs  considerably  in  the  different  specimens ;  its 
width  is  from  less  than  three-fourths  of  an  inch  to  an  inch  and  a  half,  and  its 
length  measures  from  less  than  three-fourths  of  an  inch  to  an  inch.  The  speci- 
men figured  on  plate  9,  figures  8  to  12,  has  a  width  of  one  inch  and  five- 
eighths,  by  a  length  of  an  inch  and  a  quarter,  but  specimens  of  these  dimen- 
sions are  of  unusually  large  size,  and  of  rare  occurrence. 

Formation  and  Locality. — This  species  occurs  in  the  Corniferous  limestone  at  and  near  the  Falls  of 
the  Ohio,  in  Indiana  and  Kentucky;  it  appears  in  some  strata  pretty  abundantly,  though  good  and  well 
preserved  specimens  are  somewhat  rare.  This  species  was  named  in  honor  of  Judge  Grier,  of  Dayton, 
Ohio,  who  presented  Prof.  Hall  with  good  specimens  from  that  locality. 

Spirifera  hobbsi.    N.  SP. 

Plate  X.,  figures  21,  22,  26  to  30,  and  35  and  40. 
Spirifera  varicosa  var.,  Hall.     Pal.  N.  Y.,  Vol.  4,  p.  206,  pi.  31,  fig.  23. 

Shell  transverse,  semi-oval ;  width  exceeding  the  length  considerably,  some- 
times having  its  double  size  ;  hinge-line  equalling  the  greatest  width  of  the 
shell,  and  terminating  in  salient,  mostly  mucronate  angles.  Surface  plicate. 

Ventral  valve  much  elevated,  sub-pyramidal  ;  most  prominent  at  the  beak 
or  a  little  in  front  of  it.  The  beak  is  not  incurved,  or  at  least  only  slightly 
so ;  mesial  sinus  well  defined  and  forming  a  deep  triangular  groove,  with  an 
acute  angle  in  the  bottom,  resembling  that  of  Spir.  byrnesi,  but  not  so  much 
produced  at  the  front.  Cardinal  area  straight  and  large,  with  sharply  angular 

OEOL.    SUK. — 1C 


1'22  PALAEONTOLOGY    OF    KENTUCKY. 

margins,  vertical  and  extending  to  the  cardinal  extremities,  where  it  does  not 
form  an  acute  angle,  but  still  maintains  a  visible  height,  which  is  not  suffi- 
ciently shown  in  figure  29,  plate  10.  Triangular  fissure  of  moderate  size. 

Dorsal  valve  very  little  convex,  and  flattened  towards  the  cardinal  extremi- 
ties, and  of  equal  size  with  the  ventral  valve.  The  mesial  fold  elevated, 
rounded  in  the  upper  part,  but  somewhat  flattened  towards  the  front. 

Surface  marked  by  about  twelve  prominent  and  rounded  or  sub -angular 
plications  on  each  side  of  the  mesial  fold  and  sinus,  which  are  crossed  by 
strong,  lamellose,  imbricating,  concentric  striae  and  lines  of  growth,  which  give 
the  shell  a  rugose  appearance.  Only  the  plications  next  to  fold  and  sinus 
reach  to  the  apex,  the  lateral  ones  run  out  along  the  margins  of  the  area. 
Length  of  shell  about  half  of  an  inch  and  even  less ;  its  width  measures  from 
one  inch  to  one  inch  and  one-eighth. 

Prof.  Hall  has  given  in  Pal.  N.  Y.,  vol  4,  plate  31,  subfigure  23,  the  ventral 
valve  of  a  shell  which  he  calls,  on  page  206  of  the  same  volume,  Spirifera 
varicosa,  variety.  His  description  is  short  and  incomplete.  His  figure  shows 
some  similarity  with  the  present  species,  but  it  differs  in  its  enlarged  sinus 
towards  the  front,  and  also  by  the  area,  which,  in  Hall's  specimens,  is  partly 
concave,  while  that  of  mine  is  always  straight. 

Formation  and  Locality. — Found  in  the  upper  strata  of  the  Devonian  limestone  around  the  Falls 
of  the  Ohio,  in  Kentucky  and  Indiana.  It  is  rare,  and  seldom  found  in  well  preserved  specimens.  I 
named  this  species  after  Orlando  Hobbs,  Esq.,  of  JefFersonville,  Ind.,  who  is  an  ardent  student  and  collector. 

Spirifera  knappiana.    N.  sr. 

Plate  VII.,  figure  14. 

Shell  sub-circular,  gibbous  ;  hinge-line  shorter  than  width  of  shell ;  cardinal 
extremities  rounded. 

Ventral  valve  gibbous  in  the  upper  part,  and  regularly  curving  to  the  front 
and  sides.  Mesial  sinus  well  defined  from  front  to  apex  of  beak,  somewhat 
shallow  and  rounded ;  it  contains  two  faintly  marked  plications.  Beak  of 
medium  size  and  curved  over  the  area,  which  is  high  and  concave,  extending 
over  about  two-thirds  of  the  entire  width  of  the  shell ;  fissure  of  medium 
size. 

Dorsal  valve  gibbous,  regularly  convex  on  the  sides,  a  little  flattened  at  the 
cardinal  extremities ;  mesial  fold  prominent  and  well  defined  to  apex  of  beak, 
containing  on  its  middle  a  well  marked  depression  ;  beak  small,  slightly  arched 
over  the  sub-linear  area,  which  is  somewhat  concave. 

Surface  marked  by  from  six  to  eight  rounded  plications  on  each  side  of 
fold  or  sinus  ;  they  are  crossed  by  imbricating  lines  or  striae,  which  have  irreg- 
ular distances  in  the  upper  part,  but  become  regular  and  close  set  in  the  front 


123 

part.     The  whole  surface  is  covered  with  very  fine  closely  set  radiating  striae, 
but  there  are  no  elongated  nodes  or  tubercles,  as  in  conradana. 

The  cardinal  area  is  densely  covered  with  fine  vertical  striae.  Any  one  com- 
paring the  description  of  this  species  with  that  of  conradana,  will  see  that  both 
species  agree  in  a  great  many  essential  characters,  but,  in  spite  of  that,  there 
are  several  points  of  difference  of  sufficient  value  to  entitle  Sp.  knappiana  to 
the  full  rank  of  a  species.  These  points  of  difference  are  : 

1.  The  plications  in  the  mesial  sinus  and  the  depression  of  the  mesial  fold 
found  in  knappiana  are  wanting  in  conradana. 

2.  The  elongated  nodes  or   tubercles  of    conradana  are  not  possessed  by 
knappiana. 

3.  The  difference  between  width  and  length  is  greatly  less  in  knappiana  than 
in  the  other  species. 

4.  The   plications  in  knappiana  are    more  prominent  than   those  of   con- 
radana. 

6.  The  knappiana  has  fine  regular  radiating  striae  instead  of  the  tubercles 
of  conradana. 

Some  more  differences  might  be  pointed  out,  but  I  consider  those  enumer- 
ated here  fully  sufficient  to  enable  anybody,  even  the  beginners  in  geological 
science,  to  distinguish  this  new  species  from  the  preceding  one  without  the 
least  doubt  or  trouble.  With  no  other  Devonian  Spirifer  could  Sp.  knappiana 
be  confounded  ;  it  is,  therefore,  easily  identified. 

Formation  and  Locality. — This  elegant  species  is  associated  with  conradana,  with  which  it  is  un- 
doubtedly nearest  related,  in  the  Corniferous  limestone  of  Kentucky,  but  it  is  of  rare  occurrence,  at  least 
it  is  not  represented  in  any  collection  of  the  Falls  Cities  but  my  own  and  that  of  Major  Wm.  J.  Davis. 
I  have  named  it  in  honor  of  the  late  Dr.  James  Knapp,  who  collected,  during  his  life-time,  one  of  the  finest 
geological,  or  rather  palseontological  cabinets,  not  only  of  Louisville,  but  of  the  whole  south  and  west. 
He  furnished  many  of  the  eastern  prominent  palaeontologists  with  valuable  material  for  their  palasontolog- 
ical  writings,  and,  in  this  manner,  rendered  great  services  to  science.  His  collection  contained  a  great 
number  of  very  valuable  specimens  of  Devonian  and  Silurian  crinoids,  shells  and  corals,  which  were  not 
to  be  found  in  any.  cabinet  outside  of  Louisrille. 

Spirifera  macconathii.    N.  SP. 

Plate  XI.,  figures  1  to  6. 

Shell  transverse,  sub  triangular  or  semi-elliptical ;  hinge-line  much  ex- 
tended ;  extremities  often  mucronate ;  valves  unequal  in  depth ;  area  large; 
surface  plicate. 

Ventral  valve  elevated  at  the  beak  ;  abruptly  sloping  to  the  front  and  lateral 
margins,  but  with  little  convexity.  Area  one-third  as  high  as  long,  and  only 
slightly  concave ;  fissure  about  twice  as  high  as  wide,  and  reaching  to  apex  of 


124  PALEONTOLOGY    OF    KENTUCKY. 

valve ;  beak  minute.  Mesial  sinus  well  defined,  but  shallow,  and  flattened  at 
the  bottom,  with  sub-angular  margins  rapidly  widening  towards  the  front, 
where  it  is  somewhat  produced. 

Dorsal  valve  depressed,  convex,  most  convex  above  the  middle  ;  cardinal  ex- 
tremities often  inflected ;  beak  not  prominent,  incurving  over  the  linear  area. 
Mesial  fold  well  defined  and  rounded,  but  flattened  on  top  towards  the  front. 
Surface  marked  by  from  eighteen  to  twenty  simple  rounded  plications  on  each 
side  of  the  mesial  fold  and  sinus  ;  only  few  of  these  ribs  reach  to  the  beak,  the 
others  run  out  on  the  margins  of  the  cardinal  area. 

This  species  agrees  in  many  points  with  Prof.  Hall's  description  of  Spirifera 
macronata,  in  Pal.  N.  Y.,  volume  4,  page  231,  but  it  differs  by  its  smaller 
number  of  ribs,  which  in  this  species  never  exceeds  twenty,  while  macronata 
has  from  twenty-five  to  thirty -five.  The  area  of  macronata  is  straight,  while 
that  of  mcconathii  is  always  concave,  and  the  surface  of  this  last  species  is 
generally  smooth,  while  the  surface  of  the  former  is  covered  by  several  lamel- 
lose  imbricating  lines  of  growth. 

Formation  and  Locality. — Found  in  the  upper  strata  of  the  Devonian  limestone,  at  and  near  the 
Falls  of  the  Ohio,  in  Kentucky  and  Indiana.  It  is  somewhat  rare,  at  least  in  well  preserved  specimens. 
Named  after  Prof.  W.  J.  McConathy,  of  Louisville,  Ky.,  who  has  gathered  a  very  valuable  collection  of 
the  Devonian  and  Silurian  fauna  from  the  Falls  of  the  Ohio. 

Spirifera  marionensis.    SHUMARD. 

Spirifer  marionensis,  Shumard.     Geol.  Kep.  of  Mo,  p.  203 — 1855. 
Spirifer  marionensis,  Hall.     Geol.  Rep.  of  Iowa,  p.  511 — 1858. 

Shell  of  medium  size,  nearly  semi- circular,  moderately  gibbous  ;  length  about 
equal  to  two-thirds  of  the  greatest  width  ;  valves  almost  equally  convex ; 
hinge-line  longer  than  greatest  width  of  shell;  cardinal  extremities  pointed, 
and  sometimes  mucronate.  Ventral  valve  broadly  semi- elliptical  or  semi- 
circular, greatest  convexity  above  the  middle ;  umbo  gibbous ;  beak  pointed 
and  incurved ;  sinus  well  defined,  angular  and  narrow  at  the  beak,  becoming 
broad  and  shallow  below,  and  marked  by  two  or  three  dichotomizing  plica- 
tions ;  area  narrow ;  sides  nearly  parallel  and  extending  to  the  hinge-extremi- 
ties, striated  transversely ;  foramen  broadly  triangular ;  base  greater  than  the 
height. 

Dorsal  valve  regularly  convex ;  flattened  towards  the  cardinal  extremities ; 
mesial  elevation  very  moderate,  marked  by  two  or  three  plications  above, 
which  bifurcate  below.  Surface  marked  by  from  twelve  to  twenty  rounded 
and  little  elevated  plications  on  each  side  of  the  mesial  fold  and  sinus.  Plica- 
tions increasing  by  bifurcation  either  near  umbo  or  near  base. 

Concentric  lines  of  growth  cover  the  surface,  also  fine  radiating  striae,  both 
of  which  give  the  shell  a  granulose  appearance. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS. 

This  species  is  subject  to  some  variations  in  different  localities ;  but  its  nar- 
row, almost  linear  area,  its  mucronate  cardinal  extremities,  its  shallow  sinus 
and  slightly  elevated  fold,  both  of  which  are  covered  by  dichotomizing  plica- 
tions, serve  to  distinguish  it  from  all  other  Spirifera  with  which  it  is  asso- 
ciated. It  might  be  confounded  with  Spir.  parryanus,  which  has  its  sinus 
and  fold  also  covered  by  dichotomizing  plications*  but  which  has  only  single 
ribs  on  its  lateral  parts. 

Formation  and.  Locality. — Pound  in  the  rotten  hornstone  in  upper  portion  of  the  Devonian  for- 
mation, at  and  around  the  falls,  in  Kentucky  and  Indiana.  It  is  an  exceedingly  rare  species ;  the  only 
specimen  known  as  found  in  our  rocks  was  found  by  Major  Wm.  J.  Davis,  on  the  Indiana  shore  of  the 
river,  just  below  the  Falls  of  the  Ohio. 

Spirifera  medialis.    HALL. 

Plate  XXVI.,  figures  2  to  5. 

Detthyris  medialis,  Hall.     Geol.  Kep.  4t,h  Dist.  N".  Y.,  p.  208—1843. 
Spirifer  medialis,  Hall.     Tenth  Report  on  State  Cab.,  p.  164. 

Compare  Delthyris  audacula,  Conrad.     Jour.  Acad.  Nat.  Sci.  Phil.,  Vol.  VIII.,  p.  262. 
Spirifera  medialis,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  p.  227—1867. 

Shell  of  medium  size  or  larger ;  sub- triangular,  semi-circular  or  semi-ellip- 
tical ;  hinge-line  longer  than  greatest  width  of  shell  below;  cardinal  extremities 
extended,  often  mucronate;  shell  moderately  convex  or  ventricose.  Surface 
plicated. 

Ventral  valve  somewhat  more  convex  than  the  dorsal ;  beak  prominent, 
elevated  above  the  hinge-line,  and  only  slightly  incurved  at  the  apex  ;  cardinal 
area  in  our  specimens  of  medium  size,  having  the  shape  of  an  irregular  pen- 
tagon, of  which  the  two  sides  at  the  cardinal  extremities,  in  the  specimen 
before  me,  measure  about  two  lines  ;  its  margins,  sloping  down  from  the  beak, 
are  almost  straight,  but  sharply  denned ;  the  area  is  almost  flat  except  near 
the  beak,  where  it  is  slightly  curved ;  it  is  covered  by  longitudinal  striae,  and 
divided  in  the  middle  by  a  triangular  fissure,  which  is  twice  as  high  as  wide  at 
its  base,  and  which  reaches  to  the  apex  of  valve.  Mesial  sinus  is  of  moderate 
width,  but  rather  deep ;  it  reaches  to  the  apex,  and'  is  generally  rounded  but 
sometimes  flattened  at  the  bottom  ;  its  margins  are  angular  and  well  defined. 

Dorsal  valve  moderately  convex  or  gibbous ;  the  greatest  convexity  above 
the  middle,  from  where  it  slopes  in  a  gentle  curve  to  the  lateral  and  basal  mar- 
gins, except  at  the  cardinal  angles,  where  it  deflects  a  little,  and  forming  a 
slight  depression  ;  beak  small  and  slightly  incurved ;  area  linear  and  well 
defined.  Mesial  elevation  prominent  and  sharply  defined,  rising  abruptly  at 
its  sides,  rounded  or  slightly  flattened  on  top.  Surface  ornamented  by  about 
twenty-five  rounded,  simple  plications  on  each  side  of  the  mesial  fold  or  sinus, 
of  which  the  principal  ones  are  sometimes  marked  by  a  small  thread-like 


126  PALEONTOLOGY    OF    KENTUCKY. 

groove  along  their  center,  a  feature  most  common  on  the  ventral  valve.  Near 
the  lateral  and  basal  margins  there  are  several  strong  concentric  lines  of 
growth,  which  give  to  that  part  of  the  surface  a  strongly  imbricate  character. 
This  shell  is  subject  to  many  and  extreme  variations  in  the  extent  of  the  hinge- 
line,  convexity  of  the  valves,  height  of  area,  and  the  incurving  of  the  beak. 

Formation  and  Locality. — Occurs  in  the  Corniferous  limestone  at  and  around  the  Falls  of  the  Ohio 
in  Kentucky  and  Indiana.  It  is  an  exceedingly  rare  species  in  our  rocks ;  only  few  specimens  have  been 
found  in  Clark  county,  Indiana. 

Spirifera  mucronata,    CONRAD. 

Plate  XXXI.,  figures  10  and  11. 

In  the  collection  of  the  late  Dr.  James  Knapp  was  a  Spirifera  showing  the 
closest  resemblance  to  Spirifera  mucronata.  The  Doctor  claimed  that  he  found 
it  somewhere  between  Watson's  Station 'and  Charlestown,  in  Clark  county, 
Indiana.  When  he  found  it,  he  directly  identified  it  as  Spir.  mucronata,  and 
being  aware  of  the  fact  that  this  species  had  never  been  found  here,  he 
marked  it  as  soon  as  he  reached  home.  I  am  fully  convinced  that  the  Doctor 
found  the  specimen  as  he  stated,  but  it  is  possible  that  the  specimen  was  not 
a  Spir.  mucronata. 

The  Doctor  loaned  the  shell  to  me  for  illustration,  but  he  took  it  away  before 
I  had  time  to  examine  it  more  carefully.  Thus  I  had  no  opportunity  to  gain 
access  to  the  specimen  in  question,  and  I  am,  therefore,  not  able  to  give  a 
description  of  said  shell.  If  it  is  really  a  Spir.  mucronata,  it  is  certainly  the 
first  one  ever  found  in  our  rocks. 

Spirifera  oweni.    HALL. 

ft ' 

Plate  VII.,  figures  1  to  10. 
Spirifera  oweni,  Hall.     Pal.  N.  Y.,  Vol.  IV.,  page  197,  pi.  29,  figures  1  to  8. 

Shell  more  or  less  ventricose  in  its  different  stages  of  growth,  somewhat 
transversely  Oval,  semi-elliptical  or  sub-quadrate;  hinge-line  about  equal  to 
width  of  shell;  cardinal  extremities  rounded  or  angular.  Surface  plicated. 

Ventral  valve  scarcely  as  gibbous  as  the  dorsal  valve,  its  greatest  convexity 
above  the  middle  of  its  length,  and  curving  regularly  to  the  margins;  beak 
much  elevated  above  that  of  the  opposite  valve,  and  arching  over  the  fissure, 
but  scarcely  incurved ;  mesial  sinus  shallow,  concave,  usually  well  defined,  and 
reaching  distinctly  to  the  apex.  Area  high,  concave,  elevated  and  continuing 
to  the  hinge-extremities ;  foramen  or  fissure  large,  reaching  to  the  apex,  and 
sometimes  partially  filled  by  the  thickening  of  the  dental  plates. 

Dorsal  valve  the  more  gibbous,  the  greatest  convexity  in  the  middle,  and 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  127 

curving  regularly  to  the  front  and  lateral  margins,  and  usually  a  little  flattened 
or  sometimes  concave  towards  the  cardinal  extremities  ;  mesial  fold  prominent, 
rounded,  with  a  longitudinal  depressed  line  along  the  middle.  Area  narrow, 
vertical,  or  in  plane  of  the  longitudinal  axis. 

The  surface  is  marked  by  from  fifteen  to  seventeen  rounded  or  sub-angular 
plications  on  each  side  of  the  mesial  fold  and  sinus,  and  these  are  crossed  by 
distinct  concentric  striae,  which  become  strongly  imbricating,  or  are  marked  in 
strong  imbricating  lines  of  growth  towards  the  margins.  In  well  preserved 
specimens  there  are  distinct  radiating  striae.  In  many  of  the  silicified  speci- 
mens, however,  both  the  radiating  and  concentric  striae  are  partially  or 
entirely  obliterated.  The  interior  of  the  ventral  valve  shows  two  short  and 
rather  strong  teeth,  with  the  rostal  portion  quite  solid.  The  dental  plates, 
reaching  to  the  bottom  of  the  cavity  of  shell,  curve  slightly  outwards  and 
partially  inclose  an  oval  muscular  area,  which  in  its  upper  part  is  divided  by 
a  short  medium  crest.  In  some  silicified  specimens  the  conical  spires  are 
partially  and  sometimes  entirely  preserved.  The  crura  are  widely  separated 
at  their  bases,  and  converging  somewhat  abruptly,  curve  into  the  dorsal  valve, 
making  twelve  or  more  turns,  and  producing  a  short  strong  spire.  In  well 
preserved  specimens  the  mesial  fold  and  sinus  are  usually  well  defined,  but  in 
some  of  the  more  gibbous  forms  the  sinus  is  very  broad,  and  one  or  two  of  the 
plications  on  each  side  are  involved  in  the  sides  of  the  depression,  at  the 
same  time  the  mesial  fold  is  very  prominent,  rounded,  and  sloping  almost 
imperceptibly  into  the  general  contour  of  the  convexity  of  valve. 

This  species  has  been  generally  referred  to  Spir.  laemcosta  of  Lamarck,  from 
which  it  differs  in  being  less  gibbous,  having  a  greater  number  of  plica- 
tions, and  having  also  a  depressed  line  along  the  middle  of  the  mesial  fold  of 
the  dorsal  valve.  It  may  be  easily  distinguished  from  Spir.  euruteines,  with 
which  it  is  associated,  by  its  narrower  and  much  more  arcuate  area  and  less 
angular  plications.  Some  specimens  show  remains  or  traces  of  a  faintly  im- 
pressed line  along  the  center  of  each  plication.  (Hall.) 

Formation  and  Locality. — Found  in  great  abundance  and  beauty  in  the  Devonian  limestone  in 
Kentucky  and  Indiana,  around  the  Falls  of  the  Ohio.  Specimens  showing  the  internal  spiral  coils  well 
preserved  in  silicified  shells  are  not  very  rare.  This  species  was  named  by  Prof.  Hal!  in  honor  of  D.  D. 
Owen,  the  former  State  Geologist  of  Kentuc' 


130  PALEONTOLOGY    OF    KENTUCKY. 

length,  reaching  to  the  apex  of  the  beak,  the  others  are  interpolations  and 
considerably  shorter,  they  reach  only  to  the  umbo.  The  bifurcations  on  the 
dorsal  valve,  and  the  interpolations  on  the  other  one,  are  so  plainly  marked 
that  they  must  be  observed  at  the  first  glance.  The  fine  radiating  striae  cover 
fold  and  sinus  as  well  as  the  other  part  of  the  valves  ;  towards  the.  front  their 
number  is  increased  by  interpolation,  not  by  bifurcation.  Prof.  Hall  mentions 
concentric  striae,  of  which  I  have  not  noticed  the  slightest  trace,  though  I 
possess  a  specimen  showing  the  surface-markings  most  perfectly. 
'  This  species  has  some  similarity  with  Spir.  eudora  of  the  Niagara  formation, 
but  it  is  easily  distinguished  from  the  latter  by  its  elevated  beak,  its  peculiar 
plications,  and  less  gibbosity. 

Formation  and  Locality. — Occurs  in  the  upper  strata  of  the  Niagara  rocks,  in  the  quarries  east  of 
Louisville,  Ky.,  where  it  is  found  in  well  preserved  specimens;  but  it  is  extremely  rare.  Less  than  a  dozen 
of  specimens  are  so  far  found,  which  belong  either  to  my  own  cabinet  or  to  that  of  the  late  Dr.  James 
Knapp,  of  Louisville,  Ky.,  who  furnished  Prof.  Hall  with  the  types  for  his  figures  and  descriptions.  I 
have  never  heard  of  its  occurrence  at  any  other  place. 

Spirifera  radiata.     SOWERBY. 

Plate  XXIX.,  figures  13,  14,  15  and  16. 

Spirifer  radiatus,  Sowerby.     Silurian  System,  p.  637,  pi.  12. 
Delthyris  radiatus,  Hall.     Geol.  Kep.  4th  Dist.  N.  Y.,  p.  105—1843. 
Spirifer  radiatus,  Hall.     Pal.  N.  Y.,  Vol.  2,  pp.  66  and  265—1852. 
Spirifera  radiata,  Hall.     Ind.  llth  Kep.  of  State  Geologist,  page  296,  plate  24,  figures  20  to  30—1881. 

Shell  variable  in  form,  sub-triangular,  rotund  or  sub-globose ;  valves  almost 
equally  convex ;  hinge-line  considerably  less  than  the  greatest  width  of  the 
shell ;  cardinal  extremities  rounded. 

Ventral  valve  gibbous,  and  curving  regularly  towards  the  anterior  and  lateral 
margins ;  greatest  convexity  above  the  middle  of  the  valve ;  mesial  sinus 
shallow  and  flat  at  the  bottom,  and,  extending  to  the  apex,  it  is  rapidly  widen- 
ing towards  the  front,  where  it  forms  a  broad  extension,  the  termination  of 
which  is  only  faintly  curved.  The  specimen  figured  on  plate  29  shows,  in 
figures  13  and  14,  the  termination  of  the  mesial  depression  and  elevation  too 
much  curved  ;  this  is  not  the  fault  of  the  draughtsman,  but  is  caused  by  the 
form  of  the  specimen,  of  which  said  figures  are  correct  copies.  Generally  the 
mesial  fold  is  flattened  in  front,  causing  the  straight  termination;  but  this 
M-im<*n  had  the  fold  rounded  to  the  front,  which  produced  the  strongly 
curved  extension. 

The  margins  of  the  sinus  are  pretty  well  defined  in  the  umbonal  region,  but 
from  there  downwards  they  are  only  faintly  indie*  ^ft.  The  beak  is  sometimes 
considerably  elevated  above  the  hinge-line,  and  on/y  slightly  curved,  as  in  the 
specimen  figured,  while  in  others  the  cardinal  area  is  scarcely  visible,  and  the 


r 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  131 

beaks  of  both  valves  almost  touching  each  other.  The  length  of  the  hinge  line 
is  so  variable  that  in  some  specimens  it  almost  equals  the  greatest  width  of 
the  shell,  while  in  others  it  is  so  much  reduced  that  it,  in  connection  with  the 
rounded  extremities,  and  beaks  touching  each  other,  leaves  its  generic  position 
doubtful.  Such  specimens  show  nearer  relation  to  Atrypa  than  to  Spirifera. 
The  triangular  lissure  is  also  variable  ;  sometimes  it  is  broad  in  the  base,  some- 
times long  and  narrow ;  in  some  specimens  it  is  open,  in  others  partially  or 
entirely  closed  by  a  pseudo-deltidium. 

Dorsal  valve  is  almost  as  gibbous  as  the  other  valve  ;  its  greatest  convexity 
is  below  the  umbo,  from  where  it  regularly  but  gently  curves  to  the  anterior 
and  lateral  margins.  The  mesial  fold  is  arcuate  from  beak  to  front,  pretty 
well  defined  in  its  upper  portion,  but  very  slightly  or  not  at  all  towards  the 
front ;  it  is  rounded  above  the  middle  of  the  valve,  but  flattened  and  sometimes 
even  a  little  depressed  in  the  basal  half  ;  beak  incurved  over  the  linear  area. 

Surface  marked  by  regular  fine  radiating  striae,  which  cover  also  the  mesial 
fold  and  sinus,  some  of  which  bifurcate  or  dichotomize  towards  the  front. 
Prof.  Hall,  in  his  description  of  this  species  in  the  Indiana  Report,  states,  that 
of  these  striae,  eight  or  more  occupy  the  space  of  a  line,  that  the  radii  are 
flattened,  and  that  the  interspaces  are  only  about  half  as  wide  as  the  striae. 
The  specimen  before  me,  the  same  figured  on  plate  29,  which  I  found  in  the 
quarry  near  the  new  water- works,  east  of  Louisville,  and  which  shows  the 
surface-markings  as  perfect  as  possible,  agrees  as  to  the  number  of  striae  in 
the  space  of  a  line,  but  it  differs  as  to  the  balance  of  Prof.  Hall's  observation. 
In  my  specimen  the  striae  are  not  flattened,  but  plainly  rounded,  and  the 
interspaces  are  certainly  as  wide,  if  not  wider,  than  the  radii.  It  appears  to 
me  that  the  Waldron  specimens  differ  in  some  respects  slightly  from  those  of 
our  strata.  I  have  a  good  many  Waldron  shells  before  me ;  they  show  finer 
and  closer  set  striae  than  the  Kentucky  specimens. 

In  size  this  species  is  as  variable  as  any  other  Spirifera,  or  even  more  so. 

In  the  quarries  near  our  city  we  generally  find  the  Spir.  radiata  of  small 
dimensions,  some  measuring  only  three -eighths  of  an  inch  in  length  and  one- 
half  of  an  inch  in  width,  while  the  specimen  figured  is  about  one  of  the 
largest  found  near  Louisville,  and  specimens  of  this  size  are  extremely  rare. 
In  the  Niagara  limestone  near  Waldron,  Ind.,  we  find  specimens  of  an  inch 
and  a  quarter  in  length  by  a  width  of  an  inch  and  a  half. 

Formation  and  Locality. — Found  in  the  Niagara  limestone  east  of  the  city  of  Louisville,  and  on 
the  opposite  bank  of  the  Ohio  river  in  Indiana.  But  the  finest  and  most  perfect  specimens  of  this  species 
are  found,  even  abundantly,  near  "Waldron,  Indiana. 


132  PALAEONTOLOGY    OF    KENTUCKY. 

Spirifera  sculptilis.     HALL. 

Plate  XXXI.,  figure  13. 

Delthyris  sculptilis,  Hall.     Geol.  Kep.  of  4th  Dist.  N.  Y.,  p.  202—1843. 
Spirifera  sculptilis,  Hall.     Pal.  N.  Y.,  Vol.  4,  p.  221,  pi.  35—1862-1866. 

Shell  gibbous ;  valves  sub-equally  convex,  semi-elliptical  or  sub-triangular ; 
hinge-line  longer  than  greatest  width  of  shell,  and  prolonged  into  mucronate 
extensions ;  length  about  one-half  the  width  on  the  hinge-line.  Surface 
coarsely  plicated. 

Ventral  valve  regularly  convex,  arcuate ;  beak  arcuate  over  a  sub-linear  area 
of  moderate  height,  extending  to  the  limits  of  the  cardinal  line :  mesial  sinus 
strongly  defined,  sub-angular. 

Dorsal  valve  regularly  convex,  the  greatest  convexity  in  the  middle,  and 
regularly  arcuate  from  beak  to  base;  mesial  fold  abruptly  and  strongly 
elevated,  with  the  summit  flattened  or  grooved ;  beak  incurved;  area  very 
narrow. 

Surface  strongly  marked  by  three,  four  or  five  abruptly  elevated  angular, 
plications  on  each  side  of  the  mesial  fold  and  sinus,  leaving  a  somewhat  wide 
corrugated  space  at  the  cardinal  angles.  The  plications  bordering  the  sinus 
are  stronger,  more  elevated,  and  continuing  distinct  quite  to  the  apex.  The 
shell  is  concentrically  marked  by  strong,  imbricating  lamellose  striae,  which 
are  abruptly  bent  backwards,  and  much  elevated  in  crossing  the  plications, 
giving  them  a  sub-nodose  character.  In  the  bottom  of  the  sinus  these  striae 
have  often  a  distinct  backward  bend,  with  a  slight  elevation  indicating  an 
incipient  plication,  which  corresponds  with  the  depression  in  the  mesial  fold. 
This  species  is  readily  recognized  by  its  few  strong  plications,  and  the  wide 
space  at  the  cardinal  extremities  marked  only  by  the  concentric  striae.  (Hall.) 

Formation  and  Locality. — Found  in  the  upper  strata  of  the  Devonian  formation,  around  the  falls, 
in  Kentucky  and  Indiana,  where  it  is  of  very  rare  occurrence.  My  figure  is  taken  from  a  very  fine  and 
well  preserved  ventral  valve,  showing  the  inside  and  the  hinge  in  perfect  order.  This  specimen  I  found 
at  the  Falls  of  the  Ohio,  in  the  so-called  rotten  hornstone,  which  furnishes  the  best  preserved  fossils. 

Spirifera  segmenta.     HALL. 

Plate  XIII.,  figures  36,  37  and  38. 

Spirifer  segrHentus,  Hall.     Tenth  Kep.  on  the  State  Cab. — 1857. 
Spirifer  segmentus,  Hall.     Descript.  of  New  Pal.  Fossils,  p.  91 — 1857. 
Spirifera  segmenta,  Hall.    Pal.  N.  Y.,  Vol.  4,  p.  207,  plate  31. 

Shell  transverse,  semi-oval;  length  less  than  half  the  width;  hinge-line 
equalling  the  greatest  width  of  shell,  and  terminating  in  salient  angles.  Sur- 
face plicate. 

Ventral  valve  much  elevated,  sub-pyramidal,  most  prominent  at  the  beak, 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  133 

which  is  not,  or  at  least  very  seldom,  incurved  ;  mesial  sinus  strongly  defined, 
shallow  and  nearly  flat  in  the  bottom  ;  its  sides  are  straight,  which  give  it  a 
triangular  form,  in  which  the  sides  are  about  once  and  one-half  as  long  as  the 
base.  Area  very  large,  with  sharply  angular  margins,  and  greatly  inclined 
forward,  and  nearly  of  the  same  size  as  the  exterior  of  the  valve ;  the  fissure 
is  high  and  large,  almost  equalling  in  size  the  mesial  sinus. 

Dorsal  valve  depressed,  convex  and  flattened  towards  the  cardinal  extremi- 
ties, larger  than  the  ventral  valve,  semi-elliptical  in  form,  with  a  low  but 
sharply  defined  mesial  fold,  which  is  barely  flattened  upon  the  summit.  The 
proportions  in  height  of  area,  length  of  ventral  and  length  of  dorsal  valves,  is 
about  as  five,  six  and  seven. 

Surface  marked  by  twenty  or  more  simple,  rounded  or  sometimes  sub-angu- 
lar plications  on  each  side  of  the  mesial  fold  or  sinus,  the  lateral  ones  of  which 
do  not  reach  the  beak,  but  run  out  along  the  margins  of  the  area.  In  its  per- 
fect condition  the  shell  has  been  marked  by  fine  concentric  striae,  traces  of 
which  are  still  preserved,  together  with  stronger  imbricating  lines  of  growth. 
(Hall.) 

This  species  is  associated  with  Spir.  varicosa,  and  its  younger  and  smaller 
specimens  may  sometimes  be  mistaken  for  those  of  that  species ;  But  Spir. 
segmenta  differs  from  Spir.  varicosa  in  the  following  points : 

1.  In  Spir.  segmenta  the  area  is  always  straight  and  greatly  inclines  towards 
the  front,  which  easily  distinguishes  it  from  almost  any  other  species  of  Spiri- 
fera,   except  some  forms  of  euruteines.      In  Spir.   varicosa  the  cardinal  area 
is  markedly  concave  and  stands  at  right-angles  to  the  margins. 

2.  Spirifera  segmenta  has   twenty  and  more  plications  on  each  side  of  the 
mesial  fold  and  sinus,  while  Spir.  varicosa  has  only  from  eight  to  ten  ribs  in 
each  half  of   each  valve ;  then,   again,  the  plications  of  segmenta  are  always 
smoother  than  those  of  varicosa. 

3.  In  Spir.  segmenta  the  dorsal  valve  exceeds  in  size  the  ventral  valve,  which 
is  not  the  case  in  Spir.  varicosa. 

Besides  these,  there  are  several  other  differences  which  the  student  of  palaBon- 
tology  will  soon  find,  whenever  he  closely  examines  numerous  specimens  of 
both  species. 

The  older  and  larger  specimens  of  this  species  resemble  some  Spir.  euruteines, 
but  it  is  easily  distinguished  from  euruteines  by  the  frontward  inclination  of 
its  area,  by  its  greater  transversity,  by  its  smaller  size  and  more  numerous 
plications,  and  by  its  dorsal  valve  exceeding  in  size  the  ventral  one.  All  three 
species  are  found  associated,  and  the  Spir.  segmenta  forms  a  kind  of  connect- 
ing link  between  the  two  other  species. 

Prof.  Hall  states  that  Spir.  segmenta  finds  its  nearest  analogue  in  Spir. 
angusta  of  the  Hamilton  group,  and  indicates  that  both  species  might  be 


154  PALEONTOLOGY    OF    KENTUCKY. 

identical.  Specimens  in  the  collection  of  the  late  Dr.  James  Knapp,  marked 
by  Prof.  Hall  himself  as  Spir.  angusta,  can  not  be  distinguished  from  Spir. 
segmenta.  If  his  original  Spir.  angusta  are  really  identical  with  those  marked 
by  him  as  of  the  same  species  in  Dr.  Knapp' s  cabinet,  we  must  consider  seg- 
menta and  angusta  as  belonging  to  one  and  the  same  species.  Both  are  origi- 
nally described  by  Prof.  Hall  in  his  tenth  report  on  the  State  Cabinet,  in  1857, 
and  it  is  therefore  difficult,  if  the  identity  of  segmenta  and  angusta  should  be 
proved,  to  decide  which  of  them  ought  to  be  placed  among  the  synonyms. 
Inasmuch  as  Spir.  segmenta  is  described  in  said  report  on  page  131,  while  the 
description  of  Spir.  angusta  appears  on  page  164,  the  name  segmenta  has  pre- 
cedence over  angusta. 

But  those  specimens  marked  by  Prof.  Hall  do  not  at  all  agree  with  his 
figures  in  the  4th  volume  of  the  Pal.  of  New  York,  and  it  is,  therefore,  possi- 
ble that  he  made  a  mistake  in  his  identification.  I  have  never  found  a  Spirifer 
in  our  strata  that  agreed  fully  with  Hall's  figures  of  Spir.  angusta,  where  the 
cardinal  area  inclines  so  much  forward,  and  where  the  cardinal  extremities  are 
so  mucronate.  If  Spir.  angusta  holds  good  as  a  species,  it  has,  as  far  as  I 
know,  not  been  found  near  the  Falls  of  the  Ohio. 

Formation  and  Locality. — Spir.  segmenta  is  found  in  abundance,  and  as  well  preserved  specimens, 
in  the  Coruiierous  limestone  of  Kentucky  and  Indiana,  at  and  around  the  Falls  of  the  Ohio  river. 

Spirifera  varicosa.    HALL. 

Plate  X.,  figures  11  to  20,  and  23  to  25. 

Spirifer  varicosns.  Hall.     Tenth  Rep.  on  the  State  Cab.,  p.  130 — 1857. 
Spirifer  varicosus,  Hall.     Description  of  New  Pal.  Fossils,  p.  90 — 1857. 
Spirifera  varicosa,  Hall.     Pal.  N.  Y.,  Vol.  4,  p.  205,  pi.  31. 

Shell  somewhat  semi-circular  or  semi- elliptical ;  length  equalling  or  less  than 
half  the  width;  hinge- line  equal  to  greatest  width  of  shell,  and  terminating 
in  salient  angles  or  mucronate  extensions.  Surface  plicated. 

Ventral  valve  much  the  more  convex ;  greatest  elevation  at  the  umbo,  and 
regularly  curving  to  the  front  and  to  the  lateral  margins  ;  mesial  sinus  strongly 
defined,  rather  flat  in  the  bottom ;  beak  slightly  arcuate ;  area  high,  nearly 
flat  below,  and  slightly  concave  towards  the  apex. 

Dorsal  valve  moderately  convex,  with  a  prominent,  abruptly  elevated  mesial 
fold,  which  is  flattened  on  the  summit,  and  sometimes  slightly  depressed  along 
the  center  ;  the  beak  projecting  a  little  above  the  hinge-line,  and  over  a  narrow 
area  gently  incurved. 

The  surface  is  marked  by  from  eight  to  ten  simple  and  somewhat  abruptly 
elevated  plica tions  on  each  side  of  the  mesial  fold  or  sinus;  they  are  crossed 
by  strong  lamellose,  imbricating  lines  of  growth,  which  give  a  varicose  charac- 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  135 

ter  to  the  surface,  and  where  the  shell  is  exfoliated  the  plications  are  nodose. 
In  some  specimens,  distinct,  fine  radiating  striae  can  be  observed,  but  this  is 
of  rare  occurrence.  There  is  often  a  retrorse  curving  of  the  concentric  striae 
in  the  center  of  the  mesial  sinus,  and  sometimes  a  slight  elevation  on  that  line. 
(Hall.) 

Prof.  Hall,  who  first  described  this  species,  compares  it  with  Spirifera  euru- 
teines  of  Owen.  In  regard  to  size,  the  euruteines  is  almost  twice  as  large  as 
the  varicosa,  at  least  we  find  plenty  specimens  of  the  former  species  which 
have  double  the  width  of  the  latter  one.  Spir.  varicosa  is  always  more  trans- 
verse, that  is,  the  excess  of  its  width  over  its  length  is  considerably  greater 
than  the  excess  of  the  width  over  the  length  in  Spir.  euruteines.  In  Spir. 
varicosa  the  plications  are  more  angular,  and  the  concentric  lines  of  growth 
greatly  stronger  than  in  Spir.  euruteines.  It  differs  from  the  latter  also  by  its 
abrupt  and  angular  mesial  fold.  This  species  shows  very  little  variations  in 

the  more  than  one  hundred  specimens  before  me. 

/ 

Formation  and  Locality. — Found  in  great  abundance,  and  in  most  perfectly  preserved  specimens, 
in  the  Corniferous  limestone  around  the  Falls  of  the  Ohio,  in  Kentucky  and  Indiana. 


Genus  Trematospira.    Han. 

Trematospira,  Hall.     Pal.  N.  Y.,  Vol.  3,  page  207—1859. 

Etymology :  trema,  a  foramen;  spira,  a  spire;  alluding  to  the  perforation  in  the  beak  of  the  ventral  valve. 

Shell  transverse,  elliptical  or  sub-rhomboidal,  furnished  with  internal  spires 
(arranged  as  in  Spirifera)  ;  hinge-line  shorter  than  width  of  shell ;  cardinal 
angles  rounded.  Valves  articulated  by  teeth  and  sockets  ;  beak  of  ventral 
valve  produced  or  incurved,  and  truncated  by  a  small,  round  perforation, 
separated  from  the  hinge-line  by  a  deltidium.  A  deep  triangular  pit  or  fora- 
men, beneath  the  beak  of  ventral  valve,  which  is  filled  by  beak  of  the  dorsal 
valve.  False  area  sometimes  defined.  Surface  marked  either  with  strong, 
simple  plications  or  finer  fasciculate  or  bifurcating  striae,  which  cover  also 
the  mesial  elevation  and  depression.  Shell  structure  punctate.  (Hall.) 

In  the  extension  of  the  hinge-line,  the  mesial  sinus,  the  internal  spires,  and, 
partly,  in  the  exterior  markings,  this  genus  resembles  Spirifera  and  Spiriferina. 
In  the  perforate  beak,  false  area  and  incurving  of  the  dorsal  beak  beneath 
that  of  the  other  valve,  it  resembles  Atrypa,  while  one  species  has  the  gen- 
eral aspect  of  Rhynchonella.  The  broad  triangular  foramen  for  the  recep- 
tion of  the  dorsal  beak  is  a  constant  and  conspicuous  feature  of  this  genus. 


136  PALEONTOLOGY    OP    KENTUCKY. 

Trematospira  hirsuta.    HALL. 

Plate  XVI.,  figures  15  to  19. 

Atrypa  hirsuta,  Hall.     Tenth  Kep.  on  State  Cabinet,  p.  108 — 1857. 
Trematospira  hirsuta,  Hall.     Thirteenth  Kep.  on  State  Cab.,  p.  101 — 1860. 
Athyris  (?)  chloe,  Billings.     Canada  Journal,  p.  282—1860. 
Trematospira  hirsuta,  Hall.     Pal.  N.  Y.,  Vol.  4,  pp.  274  and  275—1867. 

Shell  of  medium  size ;  sub-elliptical,  in  very  old  specimens  sub-circular  or 
sub-quadrate  ;  moderately  convex  when  young ;  increasing  in  convexity  with 
increasing  age,  and  finally  becoming  gibbous ;  sinus  and  fold  wanting  in  young 
shells,  appearing  at  a  certain  age,  and  becoming  prominent  in  old  individuals, 
which  assume  in  outline  the  exact  shape  of  Athyris  vittata. 

Ventral  valve  moderately  convex,  with  greatest  convexity  at  the  umbo,  from 
where  it  slopes  somewhat  abruptly  to  the  cardinal  margins,  and  gently  to  the 
lateral  and  basal  margins ;  the  umbo  is  prominent  and  the  beak  incurved  ;  a 
mesial  sinus  is  indicated  in  young  shells  ;  it  becomes  more  definite  with  age, 
but  remains,  even  in  very  old  specimens,  shallow  ;  this  sinus  is  undefined  in 
its  margins,  which  are  rounded,  and  which  coalesce  with  the  general  surface 
of  the  valve,  and  it  does  never  extend  further  back  than  to  a  little  behind  the 
middle  of  shell. 

Dorsal  valve  of  about  equal  convexity  with  the  ventral,  except  in  old  speci- 
mens, in  which  it  is  considerably  less  ;  greatest  convexity  above  the  middle  of 
the  valve,  from  where  it  slopes  in  a  gentle  curve  to  the  sides  and  front ;  umbo 
flat,  but  becoming  more  prominent  with  age,  and  the  beak  strongly  incurving 
into  the  other  valve  beneath  its  circular  foramen ;  a  mesial  fold  is  only  indi- 
cated in  young  specimens,  it  becomes  somewhat  more  prominent  in  older 
shells,  but  never  attains  more  than  a  moderate  elevation,  and  is  undefined  in 
its  margins,  which  are  rounded,  and  run  gradually  into  the  general  surface  of 
shell. 

Surface  ornamented  by  from  thirty  to  forty  simple,  low,  rounded,  radiating 
striae,  which  increase  from  beak  to  front  in  size  and  distance  ;  these  radiating 
striae  are  crossed  by  fine,  concentric  lines  of  growth,  and  more  distant  imbri- 
cating lamellae.  The  surface  of  the  specimens,  as  they  are  usually  found, 
is  granulose ;  but  in  perfectly  preserved  shells  it  is  covered  by  minute  setae  or 
spinules,  the  bases  of  which  remaining,  give  the  papillose  character.  The 
entire  shell  structure  is  punctate. 

The  specimen  illustrated  is  of  more  than  average  size ;  in  its  proportion  of 
width  to  length,  it  is  more  transverse  than  the  usual  form ;  but  at  the  time 
when  the  drawings  were  made  it  was  the  only  specimen  at  my  disposal. 

Formation  and  Locality. — Found  in  the  rotten  hornstone  of  the  Corniferous  group,  in  a  quarry  in 
the  eastern  portion  of  the  city  of  Louisville.  Formerly  very  rare,  but  of  late  a  good  many  very  good 
specimens  have  been  found,  so  that  my  collection  embraces  now,  at  least,  a  dozen  fair  individuals. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  137 

Trematospira  helena.    ».  SP. 

Plate  XXXII.,  figures  40  to  43. 

Shell  very  small,  broadly  ovate  or  sub-globose,  very  gibbous ;  somewhat 
longer  than  wide ;  greatest  width  below  the  middle  of  the  length,  but  not  as 
near  the  base  as  shown  in  the  figures  40  and  41.  Surface  plicated. 

Ventral  valve  regularly  curved  from  beak  to  base  ;  greatest  convexity  at  the 
middle  of  the  valve,  from  where  it  slopes  in  a  regular  curve  to  lateral  and  basal 
margins,  but  rather  abruptly  to  cardinal  lines ;  beak  in  proportion  to  the  size 
of  shell  prominent,  elevated  and  incurved  over  that  of  the  opposite  valve; 
the  place  of  the  apex  is  occupied  by  a  round,  plainly  visible  foramen  ;  lateral 
and  basal  margins  form  a  regular  curve,  with  a  slight  emargination  in  the 
central  portion  of  the  base,  which  is  not  shown  in  figures  40  and  41 ;  from  the 
umbo  to  the  front  a  mesial  depression  is  marked. 

Dorsal  valve  equal  in  convexity  to  the  other ;  most  prominent  at  the  mid- 
dle, and  curving  regularly  to  side  and  front  margins,  but  more  rapidly  to  the 
cardinal  line.  This  valve  has  also  a  mesial  depression  indicated  ;  its  umbo  is 
prominent,  and  its  beak  strongly  incurved  into  the  opposite  valve  below  the 
foramen  of  the  same. 

Surface  is  marked,  in  proportion  to  the  size  of  the  shell,  by  very  strong, 
rounded  plications,  all  of  which,  with  the  exception  of  those  in  the  mesial 
depressions,  reach  to  the  beak ;  the  ventral  valve  has  five  and  the  dorsal  valve 
four  on  each  side  of  the  sinus.  The  sinus  of  the  ventral  valve  has  in  its  bot- 
tom a  greatly  smaller  plication,  which  starts  at  the  lower  side  of  the  umbo, 
and  bifurcates  at  about  the  middle  of  its  length  ;  in  some  shells  the  mesial  rib 
does  not  dichotomize.  The  plication  in  the  mesial  depression  of  the  dorsal 
valve  is  also  somewhat  smaller  than  tfre  others,  but  the  difference  in  size  is  not 
so  marked  as  in  the  ventral  valve,  and  consequently  the  mesial  sinus  of  the 
dorsal  valve  is  not  as  conspicuous  as  that  of  the  ventral.  This  mesial  rib  of 
the  dorsal  valve  starts  at  the  beak,  and  bifurcates  below  the  umbo ;  both  prongs 
attain  at  the  base  almost  the  same  strength  as  the  adjacent  ribs,  thus  leaving 
in  a  front  view  of  the  shell  only  a  faint  indication  of  the  dorsal  sinus.  All 
these  radiating  plications  are  crossed  by  fine,  closely  set,  lamellose  concentric 
lines  of  growth,  which  give  the  surface  a  somewhat  rugose  appearance.  The 
figures,  which  are  very  defective  in  not  representing  important  features  of  this 
beautiful  little  shell,  are  enlarged  to  about  double  size. 

Formation  and  Locality. — Found  in  the  lower  strata  of  the  Niagara  group  (which  by  some  geolo- 
gists are  placed  in  the  Clinton  group),  in  the  quarries  east  of  the  city  of  Louisville,  Ky.     It  is  exceedingly 
rare,  only  three,  but  very  fine  specimens,  are  in   my  collection,  while  I   have  never  seen  it  in  any  other 
cabinet.     This  shell  has  a  close  resemblance  to  Trem.  globosa,  Hall,  from  the  Lower  Helderberg  group, 
GKOL.  SUR. — 18 


138  PALEONTOLOGY    OF    KENTUCKY. 

from  which  it  differs,  however,  by  its  smaller  size  and  smaller  number  of  plications ;  our  shell  has  only  ten 
ribs  on  each  valve,  while  that  species  has,  according  to  Prof.  Hall,  from  twelve  to  sixteen ;  then,  again, 
our  specimen  has  only  one  rib,  which  bifurcates  below  in  the  depressions,  while  Tr.  globosa  has  always 
two,  often  three,  in  said  depressions. 

Genus  Zygospira.    Han. 

Zygospira,  Hall.     15th  Regent's  Keport,  1862. 
Etymology :  zygos,  a  yoke ;  spira,  a  spire. 

This  genus  was  established  by  Prof.  Hall  to  receive  such  forms  as  Zygospira 
modesta,  Z.  cincinnatiensis  and  Z.  headi. 

Z.  modesta  is  made  the  type  of  the  genus,  which  has  great  similarity  to  Z. 
kentuckiensis,  and  which  latter,  therefore,  presents  the  main  characteristics  of 
the  genus.  The  original  description  of  this  genus,  by  Prof.  Hall,  is  cited  from 
his  15th  Regent's  Report.  It  is  to  be  regretted  that  Prof.  Hall's  valuable 
writings  are  scattered  through  such  a  great  number  of  scientific  periodicals 
and  State  reports. 

Zygospira  kentuckiensis.    ».  SP. 

Plate  XXXIV.,  figures  21  to  25. 

Shell  rather  large,  as  compared  with  other  species  of  Zygospira ;  sub-circular 
or  sub -elliptical ;  from  moderately  convex  to  gibbous ;  cardinal  lines  sloping 
towards  the  front,  forming  a  very  obtuse  angle  at  the  beaks ;  lateral  margins 
regularly  curved;  front  broadly  rounded,  with  a  straight  or  sinuate  central 
part.  Ventral  valve  larger  than  the  dorsal ;  central  part  elevated,  and  forming 
a  mesial  fold,  extending  from  beak  to  front,  not  defined  at  its  margins,  and  of 
moderate  elevation.  The  middle  line  of  this  fold  is  marked  by  a  somewhat 
broader  and  deeper  furrow,  towards  which  both  sides  of  the  fold  slightly  in- 
cline, thus  forming  a  small  mesial  sinus  on  the  top  or  summit  of  the  fold  ;  this 
central  depression  on  the  fold  extends  also  from  the  beak  to  the  front.  The 
lateral  slopes  of  the  mesial  fold  are  more  or  less  abrupt,  and  the  surface  be- 
tween fold  and  sides  becomes  flat  and  even  somewhat  concave  ;  the  umbo  is 
prominent  and  the  beak  pointed,  and,  in  most  shells,  closely  incurving  upon 
the  beak  of  the  opposite  valve,  concealing  entirely  the  hinge-area  and  its  fora- 
men. 

In  a  few  specimens  in  my  collection  the  beaks  of  both  valves  are  sufficiently 
apart  to  show  a  small  ventral  hinge-area,  with  a  small  triangular  fissure. 

The  dorsal  valve  is  moderately  convex  in  its  lateral  parts ;  its  central  portion 
is  depressed,  forming  a  mesial  sinus,  which  extends  from  the  apex  to  the 
front,  and  increases  gradually  in  depth  and  width  towards  the  base  ;  the  umbo 
is  inflated,  and  the  beak  minute  and  incurved.  The  surface  is  covered  by 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  139 

simple,  rounded  or  sub-angular,  radiating  plications,  all  of  which,  with  the 
exception  of  a  few  near  the  lateral  margins,  extend  back  to  the  beak;  they 
increase  gradually  in  strength  and  in  the  size  of  their  interspaces  towards  the 
front.  The  size  and  number  of  these  plications  is  variable  in  different  speci- 
mens. 

The  two  shells  illustrated  on  plate  34,  of  which  one  is  shown  in  figures  21, 
22  and  23,  and  the  other  in  figures  24  and  25,  are  so  different  in  form  and  in 
the  size  and  number  of  the  ribs,  that  I  would  be  justified  to  put  them  in  dis- 
tinct species  ;  but  there  are  so  many  intermediate  forms  connecting  these  two 
extremes,  which  compel  me  to  place  them  both  in  the  above  named  species. 
These  shells  have  a  somewhat  close  resemblance  to  Zygospira  modesta,  and 
are  considered  by  some  geologists  to  be  merely  a  larger  and  robust  form  of 
that  species ;  bat  it  differs  from  that  little  shell  not  only  by  its  size,  which  is 
often  more  than  twice  that  of  Z.  modesta,  but  also  by  its  convexity,  which 
often  increases  to  gibbosity,  and  also  by  its  general  aspect.  I  have  collected 
several  hundreds  of  this  shell ;  I  found  them  of  all  sizes  ;  some  very  large,  as 
shown  in  the  illustrations,  and  again  others  very  small,  not  exceeding  the  Z. 
modesta  in  size  ;  but  even  these  small  or  young  shells  differed  so  much  in  their 
whole  appearance  from  Z.  modesta,  that  I  think  it  necessary  to  separate  our 
shell  from  Z.  modesta  and  place  it  in  a  new  species  to  be  named  Z.  kentuck- 
iensis. 

Formation  and  Locality. — I  collected  this  fine  shell  in  different  places  in  Oldham  county,  Ky.,  but 
I  found  it  in  great  abundance  at  Taylor's  Station,  in  said  county,  on  the  Shelbyville  railroad,  in  the  shales 
of  the  Hudson  Kiver  or  Cincinnati  group. 

Genus  Streptorhynchus.    King. 

Streptorhynchus,  King.     Monogr.  of  Perm.  Fossils — 1850. 
Etymology:  strepto,  I  bend  or  twist;  rhynchus,  a  beak. 
Copied  from  Hall's  Pal.  N.  Y.,  Vol.  4,  page  64—1867. 

The  shells  of  this  genus  are  semi-circular  or  semi-elliptical,  concavo-convex 
or  plano-convex,  and  sometimes  bi-convex.  They  are  externally  striated,  with 
rounded  bifurcating  striae,  which  are  crossed  by  fine  concentric  lines ;  and  in 
some  forms  the  stronger  striae  are  distant,  with  finer  radiating  and  concentric 
striae  cancellating  the  intermediate  spaces.  The  ventral  beak  is  sometimes 
produced  and  bent  or  twisted,  and  the  fissure  beneath  the  beak  is  closed  or 
partly  closed  by  a  solid  deltidium,  while  the  area  is  subject  to  great  variations. 
A  narrow  area  often  exists  on  the  dorsal  valve,  but  this  is  not  a  constant  char- 
acter. This  genus  is  very  closely  allied  to  Strophomena,  the  most  obvious 
external  character  by  which  the  former  is  distinguished  being  the  irregular 
twisting  of  the  beak  of  ventral  valve. 


140  PALAEONTOLOGY    OF    KENTUCKY. 

Streptorhynchus  arctostriata.     HALL. 

Plate  XXXI.,  figures  31,  32  and  33. 
Orthisina  arctostriata,  Hall.     13th  Reg.  Report — 1860. 
Streptorhynchus  arctostriata,  Hall.     Pal.  N.  Y.,  Vol.  4,  p.  71—1867. 

Shell  of  medium  size,  semi-circular  or  semi-elliptical,  frequently  unsymmet- 
rical ;  the  proportion  of  length  to  width  differs  in  different  specimens  ;  hinge- 
line  straight,  differing  in  length  in  different  individuals,  but  in  the  average 
about  equal  to  the  greatest  width  of  the  shell ;  lateral  margins  meet  the  car- 
dinal line  usually  at  right-angles;  they  have  generally  a  compound  curve, 
concave  in  the  upper,  and  convex  in  the  lower  half.  Ventral  valve  more  or 
less  convex  towards  the  urn  bo,  and  sometimes  in  the  middle,  being  more  or 
less  flattened  towards  the  sides  and  front  of  the  shell ;  beak  often  distorted ; 
area  straight,  triangular  and  well  defined  in  its  margins ;  inclines  sometimes 
forward,  and  again,  in  other  specimens,  backwards ;  it  is  often  unequal  in  its 
two  sides  as  divided  by  the  triangular  fissure,  which  is  closed  by  a  strong  con- 
vex deltidial  plate. 

Dorsal  valve  depressed  convex,  but  in  some  shells,  partly  in  consequence  of 
distortion,  markedly  ventricose,  with  a  narrow  or  linear  area.  Surface  orna- 
mented by  sharp,  close,  radiating,  crenulated  striae,  which  increase  mainly 
by  interpolation  or  interstitial  addition. 

This  shell  is  very  variable  in  its  main  characters ;  its  beak,  generally  dis- 
torted, is  sometimes  exactly  straight;  the  cardinal  area,  unequal  in  most 
specimens,  is,  in  some  individuals,  fully  symmetrical ;  the  ventral  valve  is,  in 
most  of  our  shells,  crushed,  and  consequently  does  not  show  its  original  form ; 
while  the  dorsal  valve  of  our  specimens  is,  even  in  individuals  not  distorted, 
considerably  convex,  instead  of  the  flat  or  slightly  concave  dorsal  valve  of 
eastern  shells  of  this  species. 

Concentric  lines  of  growth  are  more  or  less  shown  on  different  shells. 

Formation  and  Locality. — Found  in  the  upper  strata  of  our  Devonian  formation,  which  by  Prof 
Hall  are  considered  as  belonging  to  the  Hamilton  group ;  it  is  a  rare  shell,  and  to  my  knowledge,  so  far, 
never  found  undistorted.  The  specimen  illustrated  on  plate  81,  figures  32  and  33,  represents  about  the 
largest  size  attained  by  this  species,  at  least  in  our  rocks. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  141 

Streptorhynchus  subplaims,     CONRAD. 

Plate  XXIX.,  figures  11  and  12. 

Strophomena  subplana,  Conrad.     Jour.  Acad.  Nat.  Sci.  Phil.,  Vol.  8 — 1842. 
Leptaena.  subplana,  Hall.     Pal.  N.  Y.,  Vol.  2.  p.  259—1852. 
Streptorhynchus  subplana,  Hall.     Trans.  Alb.  Inst.,  Vol.  4,  p.  226 — 1863. 
Streptorhynchus  subplana,  Hall,     llth  Indiana  Keport,  p.  288 — 1881. 

Shell  of  medium  size;  plano-convex,  semi-elliptical;  length  and  width  often 
equal,  but  sometimes  the  latter  exceeds  the  former  considerably  ;  hinge-line 
is  generally  longer  than  the  width  of  shell  below ;  cardinal  extremities  are 
always  somewhat  produced,  but  in  some  instances  they  become  even  nmcro- 
nate. 

Ventral  valve  moderately  convex ;  its  greatest  convexity  a  little  above  the 
middle,  from  where  it  slopes  gently  to  the  lateral  and  basal  margins  ;  the  car- 
dinal extremities  are  deflected  and  forming  a  slight  depression,  extending  from 
the  cardinal  line  obliquely  to  the  lateral  margins,  intersecting  these  about  one- 
third  the  length  of  the  shell  from  the  cardinal  extremities ;  beak  is  small  and 
not  incurved.  The  foramen  is  closed  by  a  deltidium.  The  area  extends  to  the 
extremities,  but  is  narrow. 

Dorsal  valve  is  less  convex  than  the  other ;  it  is  in  our  specimens  almost 
plane,  with  the  exception  of  the  umbonal  region  and  the  cardinal  angles,  both 
of  which  are  slightly  convex,  the  umbonal  region  by  a  natural  elevation,  and 
the  cardinal  angles  by  a  downward  deflection  of  the  extremities. 

Cardinal  area  narrow,  but  about  as  large  as  the  area  of  the  other  valve. 
Both  valves  meet  under  an  angle  of  about  sixty  degrees. 

The  surface  is  covered  by  numerous  single  thread-like  radii,  which  increase 
by  intercalation  but  not  by  bifurcation.  The  intercalated  striae  are  smaller 
than  the  original ;  they  become  equal  at  the  margin.  These  radii  are  crossed 
by  fine  concentric  striae,  and  by  a  few  marked  concentric  lines  of  growth, 
generally  two  in  number,  dividing  each  valve  into  three  concentric  zones.  Our 
specimens  differ  somewhat  in  shape  from  those  found  at  Waldron,  Indiana. 
Ours  are  somewhat  wider  in  proportion  to  length,  and  the  extremities  are  more 
produced.  The  size  of  different  specimens  differs  greatly;  the  one  illustrated  is 
of  about  maximum  size,  as  found  in  our  rocks. 

Formation  and  Locality. — Occurs  in  the  Niagara  rocks  in  the  quarries  south-east  of  the  city  of 
Louisville,  Ky.,  where  it  is  a  rather  rare  species.  Very  fine  specimens  are  found  abundantly  in  the  Niag- 
ara rocks  of  Waldron,  Indiana. 


142  PALAEONTOLOGY    OF    KENTUCKY. 

Streptorhynchus  temris     HALL. 

Streptorhynchus  tennis,  Hall.     Trans.  Alb.  Inst.,  Vol.  4,  p.  210 — 18(53. 
Streptorhynchus  tennis,  Hall.     28th  Regent's  Kep.,  p.  150 — 1879. 
Streptorhynchus  tenuis,  Hall,     llth  Geol.  Rep.  of  Ind.,  p.  287 — 1881. 

Shells  found  at  Waldron,  large ;  those  found  in  the  rocks  near  Louisville  of 
medium  size;  semi-circular  or  broadly  semi-elliptical;  cardinal  line  less  than 
greatest  width  of  shell ;  cardinal  extremities  rounded. 

Ventral  valve  moderately  convex  at  the  umbo  and  the  umbonal  region,  extend- 
ing over  about  one-third  of  the  whole  surface  of  the  valve  ;  balance  slightly 
concave  ;  cardinal  area  narrow,  but  increasing  in  height  at  the  beak  and  near 
it ;  beak  elevated  and  straight ;  triangular  fissure  of  moderate  size  and  closed 
by  a  deltidium. 

Dorsal  valve  moderately  convex ;  umbo  very  small ;  surface  depressed  near 
the  cardinal  extremities,  and  also  near  front  margin. 

Surface  ornamented  with  radiating  striae  of  -different  size,  all  fine  and 
rounded,  but  alternately  large  and  small,  which  are  strongly  curved  on  the 
lateral  portion  of  shell.  These  radii  are  crossed  by  fine  concentric  striae,  which 
give  surface  of  shell,  under  lens,  a  beautiful  rugose  character.  The  substance 
of  the  shell  is  very  thin.  Large  specimens  of  this  species  are  found  at  Wal- 
dron, Indiana,  of  which  one  individual,  according  to  Prof.  Hall's  statement, 
measures  forty  millimeters  in  length,  by  fifty  millimeters  in  width.  The  speci- 
men before  me  being  the  only  one  found  in  our  rocks,  measures  nine  lines  in 
length  by  fourteen  lines  in  width. 

Formation  and  Locality. — Found  in  the  Niagara  limestone  at  Waldron,  Indiana,  and  in  the  quar- 
ries east  of  the  city  of  Louisville,  Ky.  It  is  very  rare ;  only  few  specimens  are  so  far  found  at  Waldron, 
and  but  one  at  Louisville  j  this  last  one  belongs  to  my  collection. 

Genus  Strophodonta.    Han. 

Strophodonta,  Hall.     Pal.  1ST.  T.,  Vol.  2,  p.  63—1852. 
Etymology :  strophos,  bent ;  odous,  tooth. 

Shell  with  general  form  and  characters  of  Leptaena;  one  valve  convex,  the 
other  one  concave ;  the  concave  one  following  the  general  curve  of  the  other, 
and  being  nearly  parallel  with  the  same.  Cardinal  area  continuous,  nearly 
linear,  mostly  occupied  by  the  dorsal  valve,  striated  transversely;  foramen 
decidedly  closed  ;  ventral  valve  with  the  hinge-line  uninterrupted  ;  margins  of 
the  hinge-line  crenulated ;  area  strongly  striated  in  the  transverse,  and  more 
slightly  in  the  longitudinal  direction.  Muscular  impressions  somewhat  bilat- 
eral. 

The  crenulated  hinge-line  is  a  very  strong  distinctive  character,  since  in 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  143 

Leptaena  this  margin  is  smooth.  In  true  Leptaena,  also,  the  area  is  striated 
only  longitudinally,  that  is,  in  the  direction  of  the  hinge-line,  and  the  foramen 
is  in  part  occupied  by  a  projection  of  the  ventral  valve,  which  fills  it,  while  in 
Strophodonta  the  foramen,  if  it  ever  existed,  is  entirely  closed  by  the  growth 
of  the  dorsal  valve,  and  the  hinge-line  of  the  ventral  valve  is  straight  and  con- 
tinuous. The  striae  of  the  shell  in  many  species  of  Strophodonta  differ  from 
those  of  Leptaena,  and  some  of  the  species  are  readily  distinguished  by  this 
character  alone. 

The  chief  peculiarity  of  the  shells  belonging  to  Strophodonta  is  the  absence 
of  a  foramen  in  area  of  the  ventral  valve  ;  otherwise,  they  do  not  differ  from 
Strophomena,  which  may  hereafter  take  the  place  of  Strophodonta. 

Strophodonta  demissa.    CONRAD. 

Plate  XVIII.,  figures  10  to  16,  Plato  XXXIII.,  figure  22. 
Strophodonta  demissa,  Conrad.     Journ.  Acad.  Nat.  Sci.  Phil.,  Vol.  8 — 1842. 
Strophomena  (Strophodonta)  demissa,  Hall.     10th  Reg.  Rep.,  p.  137 — 1847. 
Strophodonta  demissa,  Hall.     Rep.  Geol.  Sur.  of  Iowa,  p  495 — 1859. 
Strophomena  demissa,  Billings.     Canadian  Journal — 1861. 
Strophomena  demissa,  Billings.     Geology  of  Canada,  p.  367 — 1863. 
Strophodonta  demissa,  Hall.     Pal.  N.  Y.,  Vol.  4,  page  101 — 1867. 

Shell  semi-elliptical,  usually  somewhat  wider  than  high,  but  in  some  speci- 
mens both  dimensions  are  equal ;  hinge-line  about  equal  to  greatest  width  of 
shell,  sometimes  differing  from  it  by  being  either  a  little  larger  or  smaller. 
The  shell  is  often  a  little  contracted  below  the  cardinal  extremities,  which 
are  sometimes  auriculate.  In  some  of  the  specimens,  the  lateral  margins  are 
nearly  straight  and  parallel  for  more  than  half  the  length  of  shell,  while  the 
lower  parts  of  the  sides  and  the  base  form  a  regular  curve. 

Ventral  valve  regularly  convex ;  greatest  convexity  a  little  above  middle  of 
the  length,  from  where  it  slopes  in  a  regular  curve  to  the  lateral  and  basal 
margins  ;  between  the  umbo  and  the  cardinal  extremities  is  a  slight  depression, 
which  only  runs  a  short  distance  from  the  cardinal  line  into  the  body  of  the' 
valve,  and  which  is  sometimes  confined  to  the  mere  deflection  of  the  cardinal 
extremities ;  umbo  is  small,  but  well  expressed,  and  the  beak  is  slightly  in- 
curved, and  reaches  somewhat  beyond  the  plane  of  the  ventral  area. 

Dorsal  valve  is  moderately  concave,  and  corresponds  in  the  general  form  of 
its  depression  with  the  convexity  of  the  ventral  valve.  The  area  of  the  ventral 
valve  is  very  variable  in  specimens  from  different  localities,  but  in  our  shells  it 
is  of  moderate  size,  forming  a  low  triangle,  and  being  curved  below  and  on 
both  sides  of  the  beak  ;  it  is  covered  by  fine  transverse,  and  still  finer  longitu- 
dinal lines  ;  no  foramen  or  fissure  is  indicated  ;  the  inner  margin  of  the  area  is 
crenulated  in  its  whole  extent.  The  dorsal  area  is  considerably  smaller  than 


144  PALEONTOLOGY    OF    KENTUCKY. 

the  ventral ;  it  is  very  narrow,  almost  linear.  The  planes  of  the  two  cardinal 
areas  are  inclined  to  each  other  in  such  a  manner  as  to  form  an  angle  of  more 
than  ninety  degrees ;  this  angle  of  the  areas  is,  however,  different  in  one  and 
the  same  specimen  according  to  the  distance  from  the  cardinal  extremities ; 
near  the  latter  it  is  smallest  and  increases  gradually,  sometimes  rapidly,  to- 
wards the  beaks,  below  which,  in  some  individuals,  they  form  no  angle  at  all, 
but  fall  ih  one  and  the  same  plane. 

The  surface  of  both  valves  is  ornamented  by  radiating  and  concentric  striae. 
Of  the  radii,  some  ten  to  twelve  are  much  stronger  and  more  elevated  than  the 
balance,  but  they  maintain  their  prominence  only  inside  of  the  umbonal  region; 
leaving  this,  they  bifurcate  directly,  which  process  is  repeated  about  half-way 
between  umbo  and  front ;  in  addition  to  this  increase  by  bifurcation,  a  further 
enlargement  in  the  number  of  finer  radii  is  attained  by  the  intercalation  of 
radiating  striae,  some  of  which  reach  even  into*  the  umbonal  region,  between 
the  before  mentioned  prominent  costae,  while  others  set  in  a  little  above  the 
second  bifurcation ;  thus  the  marginal  portion  of  the  valve  is  covered  by 
numerous  fine  striae. 

The  dorsal  valve  is  covered  by  a  similar  system  of  striae,  with  the  only 
exception,  that  in  this  valve,  between  the  first  and  second  bifurcation  of  one 
and  the  same  radius,  is  only  a  short  distance.  In  well  preserved  specimens 
the  entire  surface  of  both  valves  is  covered  by  fine  concentric  lines  of  growth, 
some  of  which  are  more  prominent,  and  divide  the  surface  into  concentric 
zones.  In  most  of  the  shells  these  concentric  lines,  with  the  exception  of  the 
most  marked  ones,  are  obliterated  by  either  silicification  or  exfoliation.  Shells 
from  different  localities  show  considerable  variation  in  form  and  size.  Our 
shells,  although  differing  in  size,  are  uniform  in  shape  and  in  the  ornamenta- 
tion of  their  surface.  With  very  few  exceptions,  they  have  all  a  brownish-red 
color,  which  is  entirely  superficial,  not  penetrating  into  the  body  of  the  shell 
to  any  extent. 

»  Formation  and  Locality. — Occurs  rather  abundantly  in  the  upper  strata  of  the  Devonian  forma- 
tion, in  Jefferson  county,  Ky.,  and  in  Clark  county,  Indiana.  Verj-  fine  and  well  preserved  specimens  are 
found,  lacking  only  the  fine  concentric  lines  of  growth.  The  illustrations  on  plate  18  represent  the  differ- 
ent sizes  of  the  shell  as  found  in  our  rocks,  and  figure  22,  plate  33,  a  very  young  specimen. 

Strophodonta  hemispherica.    HALL. 

Plate  XVIII.,  figures  4,  5  and  6. 

Strophomena  (Strophodonta)  hemispherica,  Hall.     Tenth  Keport  on  St.  Cab.,  p.  113 — 1857. 
Strophodonta  hemispherica,  Hall.     Pal.  N.  Y.,  Vol.  4,  p.  90—1867. 

Shell  of  large  size,  sub-hemispheric,  semi- elliptical  in  outline  ;  hinge -line 
equal  or  greater  than  maximum  width  of  shell;  cardinal  extremities  always 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  145 

angular,  sometimes  salient  and  auriculate  ;  length  smaller  than  the  width, 
their  proportion  about  as  four  to  five.  The  largest  specimens  measure  about 
two  inches  in  length,  by  two  inches  and  a  half  in  width.  Ventral  valve  is  very 
gibbous  ;  its  depth  is  sometimes  equal  to  half  of  its  length.  The  point  Of 
greatest  convexity  below  the  middle  of  the  length,  from  which  it  slopes  rapidly 
or  rather  abruptly  to  the  front,  and  to  the  basal  half  of  the  lateral  margins, 
while  it  curves  gently  to  the  cardinal  lines. 

The  umbo  is  more  or  less  elevated,  and  the  beak  incurved.  The  cardinal 
area  is  narrow,  and  its  margin  crenulated. 

Dorsal  valve  shallow,  concave  in  its  larger  portion,  and  only  more  abruptly 
deflected  in  a  marginal  strip  surrounding  basal  half  of  the  valve,  which  strip 
becomes  sometimes  even  geniculated. 

Surface  is  ornamented  by  fine  radiating  striae,  which  are  somewhat  unequal 
on  the  upper  and  middle  portions  of  the  ventral  valve,  but  are  fine  and  regular 
towards  the  margins.  In  some  specimens  of  the  dorsal  valve  the  striae  show 
a  tendency  to  the  alternation  of  three  or  four  finer  ones  with  a  distinctly 
stronger  one  between  ;  but  this  feature  is  not  prevalent ;  most  shells  have  the 
striae  or  their  dorsal  valve  fine,  close,  and  nearly  equal  in  strength.  Fine  con- 
centric lines  cross  the  radii  in  well  preserved  specimens,  but  they  are  usually 
obliterated.  Four  or  five  marked  wrinkles  extend  obliquely  from  the  cardinal 
extremities  into  the  body  of  the  valve,  but  reach  only  to  the  base  of  the  umbo. 
This  species  diifers  from  St.  inequiradiata  by  its  larger  size  and  greater  gib- 
bosity ;  while,  according  to  Prof.  Hall' s  statement,  it  is  so  nearly  allied  to 
Stroph.  concava,  that  it  probably  belongs  with  that  shell  in  one  and  the  same 
species. 

Formation  and  Locality. — Occurs  in  the  Corniferous  limestone  of  the  Devonian  formation  in  Jeffer- 
son county,  Ky.,  and  in  Clark  county,  Indiana.  The  specimens  for  the  figures  7,  8  and  9,  on  plate  18, 
seem  to  be  an  internal  cast  of  Strophodonta  hemispherica. 

Strophodonta  mequistriata.    CONRAD. 

Plate  XVII.,  figures  10  and  11. 

Strophomena  inequistriata,  Conrad.     Jour.  Acad.  Nat.  Sci.  Phil. — 1842. 
Strophomena  inequistriata,  Hall.     Geol.  Kep.  4th  Dist.,  p.  290 — 1843. 
Strophomena  (Strophodonta)  inequistriata,  Hall.     10th  Keg.  Kep.,  p.  142 — 1857. 
Strophodonta  inequistriata,  Hall.     Pal.  of  N.  Y.,  Vol.  4,  p.  106—1857. 

Shell  semi-oval  or  somewhat  semi  elliptical  or  semi-circular  in  outline  ;  hinge- 
line  extended  beyond  width  of  shell  below ;  cardinal  extremities  acute,  some- 
times mucronate.  In  the  specimen  before  me,  which  is  illustrated  on  plate  17, 
figure  10,  the  lateral  margins  below  the  mucronate  extremities,  and  the  basal 
margin,  form  a  regular  curve, 

GEOL.    SUE. — 19 


146  PALEONTOLOGY    OP    KENTUCKY. 

Ventral  valve  moderately  convex,  becoming  more  gibbous  in  its  center  por- 
tion from  umbo  to  front  ;  greatest  convexity  a  little  above  the  middle  of  the 
valve,  from  where  it  slopes  in  a  regular  curve  to  the  front  or  base,  and  to  the 
basal  half  of  the  lateral  margins ;  to  cardinal  line  and  to  the  rear  half  of  the 
lateral  margins  it  slopes  more  rapidly ;  the  cardinal  angles  are  reflected,  by 
which  a  shallow  concavity  is  formed  between  them  and  the  umbo ;  the  beak  is 
little  elevated  above  the  hinge-line  and  slightly  incurved  ;  the  cardinal  area  is 
narrow,  extending  to  the  extremities,  and  striate  vertically. 

Dorsal  valve  concave,  differing  greatly  in  its  depth  in  different  individuals ; 
but  usually  its  concavity  corresponds  in  general  form  with  the  convexity  of  the 
ventral  valve ;  hinge-area  very  narrow,  almost  linear,  and  of  not  more  than 
half  the  height  of  the  ventral  one  ;  no  beak  is  observed  in  this  valve. 

Surface  is  ornamented  by  radii  of  different  size  and  character,  as  may  be  seen 
in  figure  11,  plate  17.  Some  of  these  striae  are  more  prominent,  most  of  which 
extend  to  the  beak,  but  some  are  added  by  intercalation  ;  the  interspaces  be- 
tween these  stronger  striae  are  filled  by  finer  ones,  which  are  scarcely  visible  to 
the  naked  eye ;  all  the  radii  are  crossed  by  fine  concentric  striae.  The  general 
surface  character  of  the  convex  valve  is  much  like  that  of  good  specimens  of 
Strophomena  alternata,  of  the  Trenton  limestone,  but  it  does  not  appear  to  be 
subject  to  such  extreme  variations  in  respect  to  the  striae.  It  also  resembles 
greatly  in  its  surf  ace- markings  Strophodonta  textilis,  but  it  is  always  smaller, 
has  a  more  extended  hinge-line,  and  is  never  so  flat  as  that  species.  It  is  often 
confounded  with  Strophodonta  inequiradiata,  which  is  a  much  larger  species, 
with  different  internal  characters.  Its  surface  striae  are  more  delicate  than  any 
of  the  other  species. 

Formation  and  Locality. — Occurs  in  the  Corniferous  limestone  at  the  Palls  of  the  Ohio,  in  Ken- 
tucky and  Indiana. 

Strophodonta  nacrea.    HALL. 

Strophodonta  nacrea,  Hall.    Tenth  Kep.  on  St.  Cab.,  p.  144 — 1857 
Strophomena  lepida,  Hall.     Geol.  Kep.  of  Iowa,  Vol.  1,  pt.  2,  p.  493—1858. 
Strophodonta  nacrea,  Hall.    Pal.  N.  Y.,  Vol.  4,  p.  104—1867. 

Shell  below  medium  size ;  semi-elliptical,  having  a  brilliant  nacreous  luster ; 
hinge-line  crenulated,  equalling,  or  a  little  less,  than  the  greatest  width  of  shell 
below  ;  cardinal  extremities  angular.  Ventral  valve  regularly  and  moderately 
convex ;  depressed  or  slightly  concave  within  the  cardinal  angles,  caused  by  a 
slight  deflection  of  the  cardinal  extremities ;  umbo  depressed  and  the  beak 
very  small,  scarcely  elevated  above  the  hinge-line,  and  not  incurved ;  cardinal 
area  very  small  and  without  foramen. 

Dorsal  valve  concave,  corresponding  in  its  depression  with  the  form  of  tbe 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  147 

ventral  convexity ;  its  hinge-area  is  very  narrow,  almost  linear ;  no  beak  per- 
ceptible. 

Surface  smooth,  with  a  few  concentric  lines  of  growth.  Prof.  Hall  states, 
that  in  well  preserved  specimens,  traces  of  very  fine  concentric,  as  well  as  radi- 
ating striae  have  been  observed.  Our  shells  of  this  species  are  all  entirely 
silicified,  in  which  condition  the  finer  surface-markings  are  usually  obliter- 
ated. 

Formation  and  Locality.— Found  in  the  Corniferous  limestone  at  the  Falls  of  the  Ohio,  on  the 
Indiana  shore  of  the  river. 

Strophodonta  perplana.    COXRAD. 

Plate  XVIII.,  figure  17. 

Strophomena  perplana,  Conrad.    Jour.  Acad.  Nat.  Sci.  Phil.,  Vol.  8 — 1842. 
Strophomena  pluristriata,  Conrad,     ut.  sup.,  p.  259. 
Strophomena  crenistria,  Hall.     Kep.  4th  Geol.  Dist.  N.  Y.,  p.  171—1843. 
Strophomena  (Strophodonta)  fragilis,  Hall.     10th  Rep.  on  St.  Cab.,  p.  143 — 1867. 
Strophodonta  fragiiis,  Hall.     Rep.  Geol.  Surv.  of  Iowa,  p.  496 — 1858. 

Shell  semi-elliptical ;  length  varying  from  two-thirds  to  three-fourths  the 
width,  which  is  from  half  an  inch  to  two  inches  ;  slightly  concavo-convex,  and 
often  nearly  flat ;  hinge-line  equal,  or  often  a  little  greater,  than  width  of  shell 
below  ;  the  cardinal  extremities  usually  somewhat  salient,  except  in  extremely 
old  shells.  Margins  of  the  shell  often  a  little  concave  just  below  the  cardinal 
extremities,  making  the  width  there  less  than  below.  From  this  incurvation 
downwards,  the  lateral  and  basal  margins  form  usually  a  regular  curve. 

Ventral  valve  very  little  convex,  the  greatest  convexity  above  the  middle  of 
its  length,  from  where  it  slopes  in  a  gentle  curve  to  the  lateral  and  basal  mar- 
gins ;  towards  the  cardinal  angles  it  slopes  a  little  more  rapidly,  and  as  the 
extremities  are  somewhat  deflected,  the  valve  becomes  slightly  concave  between 
them  and  the  umbonal  region  ;  the  apex  is  scarcely  rising  above  the  hinge-line, 
and  slightly  incurved. 

Dorsal  valve  is  gently  concave,  but  often  almost  flat.  Area  of  the  ventral 
valve  is  usually  less  than  a  line  in  width,  and  covered  with  vertical  striae. 
Area  of  the  dorsal  valve  about  half  as  wide  as  that  of  the  ventral. 

Surface  covered  by  fine  sub-equal  striae,  those  of  the  ventral  valve  being 
finer  than  the  striae  on  the  dorsal,  extremely  sharp,  and  often  gently  undu- 
lating, increasing  both  by  bifurcation  and  by  intercalation,  and  crossed  by  fine, 
even,  concentric  striae.  Prof.  Hall  states,  that  in  some  specimens  the  longitu- 
dinal atriae  rise  at  frequent  and  regular  intervals  into  minute  granules,  which 
he  Considers  the  bases  of  minute  spines,  formerly  covering  the  ventral  valve. 
This  feature  is  not  indicated  on  any  of  our  specimens  as  far  as  I  know.  The 


148  PALAEONTOLOGY    OF    KENTUCKY. 

dorsal  valve  is  marked  by  fine,  even,  rounded  striae,  which  are  cancellated  by 
close  concentric  striae,  and  the  same  obscure  concentric  undulations,  which  are 
often  noticed  on  the  ventral  valve  near  the  umbo.  In  general  the  shell  is 
readily  recognized  by  its  nearly  flat  form  and  by  its  fine,  nearly  equal  striae. 

Formation  and  Locality. — Occurs  in  the  upper  strata  of  the  Devonian  limestone  at  the  Falls  of 
the  Ohio,  in  Kentucky  and  Indiana,  where  the  ventral  valves  are  somewhat  abundant. 

Strophodonta  profunda.    HALL. 

Plate  XXIX.,  figure  26,  and  Plate  XVII.,  figures  20  and  21. 

Leptaena  pr  ofunda,  Hall.     Pal.  N.  Y.,  Vol.  2,  p.  61,  pi.  21,  figures  4  and  5—1852. 
Strophodonta  profunda,  Hall.     20th  Regent's  Kep.,  p.  369—1867. 
Strophodonta  profunda,  Hall.     28th  Regent's  Rep.,  p.  151 — 1879. 
Strophodonta  profunda,  Hall,     llth  Geol.  Rep.  of  Ind.,  p.  289 — 1881. 

Shell  large,  broadly  semi-oval ;  width  larger  than  length ;  hinge-line  greater 
than  greatest  width  of  shell ;  cardinal  extremities  slightly  extended  and  sub- 
auriculate,  in  casts  of  ten  obtuse  or  rounded;  shell  concavo-convex.  Ventral 
valve,  according  to  Prof.  Hall's  description,  very  convex  ;  this  is  not  the  case 
with  our  shells.  In  our  specimens  the  ventral  valve  is  only  moderately  convex  ; 
in  some  individuals  the  central  portion  around  the  umbo  is  most  convex,  while 
the  balance  is  depressed,  or  even  somewhat  concave ;  in  other  shells  the  central 
portion  is  flat,  or  even  somewhat  concave,  while  the  marginal  portion  of  the 
valve  all  around,  from  one  extremity  to  the  other,  is  strongly  curved  ;  and, 
again,  in  some  specimens  the  whole  valve,  with  the  exception  of  the  cardinal 
angles,  is  regularly  and  prominently  curved  ;  in  these  shells,  the  cardinal  ex- 
tremities are  slightly  deflected,  and  the  surface  between  them  and  the  umbo 
gently  depressed  or  concave. 

Hinge  area  narrow ;  foramen  triangular,  of  moderate  size,  and  covered  by  a 
strong  deltidial  callosity. 

Dorsal  valve  corresponding  in  its  concavity  with  the  convexity  of  the  ventral 
valve.  Hinge-area  narrower  than  that  of  the  ventral  valve  ;  foramen  covered 
by  a  callosity.  Surface  marked-  by  strong,  large,  radiating  striae,  which  alter- 
nate with  four  or  five  smaller  striae,  all  of  which,  the  smaller  as  well  as  the 
larger,  increase  by  intercalation.  These  radii  are  crossed  by  fine  concentric 
lines.  In  some  specimens  the  smaller  striae  become  stronger,  forming  the 
larger  and  less  regular  striae.  The  specimen  illustrated  on  plate  17,  figure  20, 
is  one  of  the  largest  found  near  our  city. 

Formation  and  Locality. — Occurs,  in  the  Niagara  rocks  in  the  quarries  east  of  the  city  of  Louis- 
ville. It  is  not  abundant. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  149 

Strophodonta  plicata.    HALL. 

Strophodonta  plicata,   Hall.     13th   Kep.  on  St.  Cab.,  p.  90 — 1860. 

Strophodonta  plicata,  Hall.     Pal.  N.  Y.,  Vol.  4,  p,  114,  pi.  63,  figs.  30-32—1867. 

Shell  of  medium  size ;  semi-oval  or  semi-elliptical ;  concavo  convex ;  hinge- 
line  somewhat  shorter  than  the  greatest  width  of  shell ;  cardinal  extremities 
rounded ;  lateral  margins  almost  straight  or  slightly  curved ;  basal  margin 
broadly  curved.  Shell  resembling  closely,  as  far  as  form  is  concerned,  speci- 
mens of  Strophodonta  demissa,  of  medium  size  and  medium  convexity. 

Ventral  valve  moderately  convex,  with  greatest  convexity  at  about  the  mid- 
dle of  the  shell,  from  where  it  slopes  gently  to  the  cardinal  and  lateral  margins, 
and  somewhat  more  rapidly  to  the  front.  The  umbo  is  small ;  beak  little 
elevated  and  incurved  ;  cardinal  area  small,  with  a  triangular  fissure,  closed  by 
the  beak  of  opposite  valve. 

Dorsal  valve  moderately  concave,  nearly  following  the  contour  of  ventral 
valve  ;  its  cardinal  area  very  narrow,  almost  linear ;  its  beak  closing  the  ventral 
foramen. 

The  surface  is  ornamented  by  strong,  sub-angular  or  rounded  radiating 
striae,  which  increase  in  number  by  bifurcation  and  intercalation,  and  which 
are  crossed  by  a  few  concentric  lines  of  growth  near  the  margin.  This  shell 
resembles,  as  before  stated,  Stroph.  demissa,  from  which  it  is,  however,  easily 
distinguished  by  its  strong  and  prominent  striae  ;  there  is  about  the  same  pro- 
portion in  strength  between  the  striae  of  St.  plicata  and  Stroph.  demissa,  as 
between  the  striae  of  Atrypa  aspera  and  Atr.  reticularis. 

Formation  and  Locality. — Occurs  in  the  Corniferous  limestone  of  the  Devonian  formation  at  and 
around  the  Falls  of  the  Ohio,  in  Kentucky  and  Indiana,  where  it  is,  however,  a  very  rare  shell. 

Strophodonta  striata.    HALL. 

Strophomena  striata,  Hall.     Geol.  Kep.  of  4th  Dist.  N.  Y.— 1843. 
Leptaena  striata,  Hall.     Pal.  N.  Y.,  Vol.  2,  p.  259—1852. 
Strophodonta  striata,  Hall.     28th  Kegent's  Rep.,  p.  152—1879. 
Strophodonta  striata,  Hall,     llth  Geol.  Report  of  Ind.,  p.  290—1881. 

Shell  semi-elliptical ;  hinge-line  equal  or  a  little  longer  than  the  greatest 
width  of  the  shell  below  ;  dorsal  valve  slightly  convex  ;  ventral  valve  flat  or 
somewhat  concave.  Surface  covered  by  unequal,  radiating  striae,  of  which 
the  stronger  ones  have  large  interspaces,  which  are  occupied  by  one,  mostly 
by  two,  finer  radii,  all  of  which  increase  in  number  by  intercalation,  and  not 
by  bifurcation.  There  are,  sometimes,  fine  concentric  lines  of  growth  crossing 
the  radii,  but  these  are  often  obsolete.  The  specimens  of  this  species  found 
in  our  rocks  differ  somewhat  in  form  from  those  found  at  Waldron,  Indiana. 


150  PALAEONTOLOGY    OF    KENTUCKY. 

Our  shells  are  more  transverse,  and  show  a  somewhat  geniculated  base  like 
Slrophodonta  rhomboidalis,  and  besides,  are  considerably  smaller ;  but  these 
differences  are  only  the  results  of  local  conditions. 

Formation  and  Locality. — Found  in   the  Niagara  limestone  in  the  quarries  east  of  the  city  of 
Louisville,  Ky. 


Genus  Strophomena. 

Strophomena,  Rannesque.     Manuel  de  Malac.  of  Blainville — 1825. 
Etymology:  strophos,  bent;  mene,  a  crescent. 

The  Genus  Strophomena  was  established  by  Rannesque,  and  has  for  its  type 
the  S.  rugosa,  which  is  identical  with  Strophomena  rhomboidalis  of  Wahlen- 
berg,  a  species  which  ranges  from  the  Lower  Silurian  to  the  base  of  the  Car- 
boniferous system.  This  species  has  some  little  differences  in  shape  and  mark- 
ings, according  to  the  formations  in  which  it  appears.  I  have  not  been  able 
to  see  Rannesque' s  original  description  ;  but  whatever  this  may  be,  it  covers  all 
the  shells  which  are  now  included  in  this  genus  and  those  of  Hall's  genus, 
Strophodonta,  which  latter  will  certainly  be  discontinued. 

Strophomena  rhomboidalis.    WAHLENBEKG. 

Plate  XVIII.,  figures  1,  2  and  3. 

Strophomena  rhomboidalis,  Wahlenberg.     Acta.  Soc.  S.  Upsaliensis,  Vol.  8 — 1821. 
Strophomena  rhomboidalis,  Hall.     Pal.  N.  Y.,  Vol.  4,  p.  76—1867. 
See  list  of  synonyms  in  last  named  report. 

Shell  of  more  than  medium  size ;  semi-elliptical  or  sub-quadrate ;  varying 
greatly  in  its  proportions  of  length  and  breadth;  hinge-line  straight,  and 
equal  to  greatest  width  of  shell ;  cardinal  extremities  mostly  rectangular, 
sometimes  salient.  The  valves  are  geniculated,  and  the  proportions  of  the 
flattened  part  of  the  disc  and  the  recurved  part  of  the  shell  are  very  variable, 
insomuch  that  the  geniculation  is  sometimes  little  more  than  one  of  the  strong 
concentric  wrinkles.  (Hall.) 

In  the  specimens  of  this  species,  found  in  our  rocks,  there  is  not  so  much 
variation  as  stated  in  the  foregoing  description  of  Prof.  Hall.  Our  shells 
have  almost  all  the  form,  as  shown  in  the  illustrations.  They  are  sub-quadrate; 
their  lateral  margins  are  parallel  and  almost  straight,  and  the  basal  margin  is 
broadly  curved.  The  geniculation  is  usually  found  in  both  valves,  although 
in  some  specimens  the  dorsal  valve  does  not  possess  any,  but  is  entirely  plane. 
The  deflected  portion  of  the  lateral  margins  is  triangular,  with  its  apex  at  the 
cardinal  extremity ;  it  increases  gradually  towards  the  base,  where  it  equals 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  151 

in  width  the  deflected  basal  margin  ;  the  height  of  this  basal  deflection  meas- 
ures from  one- third  to  one-half  of  the  length  of  disc. 

The  ventral  valve  is  slightly  convex  at  and  around  the  umbo,  but  flat  or  even 
somewhat  depressed  between  the  umbo  and  the  geniculation ;  its  beak  is  small 
and  only  slightly  curved. 

Dorsal  valve  generally  corresponding  in  its  concavity  with  the  convexity  of 
the  ventral,  only  differing  in  the  depth  of  the  valve ;  but  in  some  shells  there 
is  an  exception  to  this  rule,  inasmuch  as  the  dorsal  valve  is  entirely  straight 
from  the  cardinal  line  to  the  level  of  the  lateral  and  basal  geniculation. 

The  surface  is  ornamented  on  the  flattened  portions  of  the  shell  by  con- 
centric, undulating,  strong  elevations,  which  are  parallel  with  the  curve  of 
the  geniculation,  and  deflect  outwards  at  the  cardinal  margin  ;  they  are  most 
prominent  in  the  portion  parallel  with  the  base,  decrease  in  strength  in  their 
lateral  course,  and  become  almost  obsolete  in  some  shells  near  the  hinge-line  ; 
their  number  is  variable,  according  to  size  and  shape  of  the  shell.  The  entire 
surface  is  covered  by  radiating  thread-like  striae.  The  triangular  fissure  of  tbe 
ventral  valve  is  partially  closed  by  a  deltidium  and  the  apex  of  the  ventral 
valve. 

Formation  and  Locality. — Occurs  in  the  upper  strata  of  the  Devonian  rocks  in  Jefferson  county, 
Ky.,  and  in  Clark  county,  Indiana.  It  is  met  with  very  often,  but  seldom  found  in  fair,  undistorted  speci- 
mens. The  individual  illustrated  is  one  of  the  largest  found  here,  though  there  is  little  difference  in  the 
size  of  our  shells  belonging  to  this  species 

Strophomena  rhomboidalis.    WAHLENBERG. 

This  species  has  been  described  from  the  Devonian  formation,  in  which  the 
conditions  for  the  development  of  the  shell  appear  to  have  been  more  favora- 
able,  inasmuch  as  the  animal  attained  a  considerably  larger  size.  Outside  of 
this  difference  we  find  no  distinction  between  the  shells  from  both  formations, 
and  there  are  no  reasons  for  a  new  description  here. 

Formation  and  Locality. — Occurs  in  the  Niagara  limestone  in  the  quarries  east  of  the  city  of  Louis- 
ville, where  it  is,  however,  rare,  and  where  it  attains  not  even  half  the  size  of  those  found  in  the  Devonian 
rocks  ia  Clark  county,  Indiana. 

Genus  Leptocoelia.    Han. 

Leptocoelia,  Hall.    Rep.  on  the  St.  Cab.  of  Nat.  Hist.— 1856. 

Copied  from  Hall's  Pal.  N.  Y.,  Vol.  3,  page  447—1859. 

Etymology:  leptos,  minute;  koilia,  belly,  in  allusion  to  the  shallow  visceral  cavity. 

Shell    inequivalve ;    variable    in  form,   usually    semi-oval    or    sub-circular, 
transverse  or  elongate,  plano-convex  or  concavo-convex ;  hinge-line  sometimes 


152  PALAEONTOLOGY    OB1    KENTUCKY. 

equal  to  greatest  width  of  shell.  Ventral  valve  convex  or  sub  angular  in  the 
middle,  with  beak  more  or  less  extended  ;  moderately  incurved.  Foramen 
terminal,  the  lower  side  formed  by  two  deltidial  pieces. 

Dorsal  valve  flat  or  concave  or  depressed  convex.  A  mesial  fold  and  sinus 
existing,  but  not  often  prominent.  Structure  of  the  shell  lamellose  or  fibrous, 
not  punctate.  Valves  articulating  by  means  of  two  strong  teeth  in  the  ventral, 
inserted  into  the  sockets  in  the  dorsal  valve,  which  are  mainly  excavated  in 
the  base  of  a  strong  cardinal  process.  Teeth  converging.  Muscular  impres- 
sion marking  a  large  ovate  or  flabelliform  area,  with  a  thin  medium  septum. 
Adductor  imprints  small. 


Leptocoelia  hemispherica. 

Plate  XXXII.,  figures  21,  22  and  23,  and  36  to  39. 
Atrypa  hemispheric^  Sovverby.     Sil.  Syst.,  p,  639  —  1839. 
Atrypa  hemispherica,  Hall.     Pal.  N.  Y.,  Vol.  2,  p.  74—1852. 
Atrypa  hemispherica,  Nicholson.     Pal.  of  Ontario,  p.  47  —  1875. 

Shell  rather  small  ;  hemispheric  or  sub-circular  ;  plicated.  Hinge-line  in 
some  specimens  extended  and  straight  ;  in  others  short  and  deflected  towards 
the  front.  Both  valves  in  the  specimens  before  me  somewhat  convex.  Surface 
ornamented  by  about  ten  to  twelve  strong,  rounded,  simple  radii,  which  in- 
crease in  strength  and  in  size  of  their  interspaces  from  apex  to  front.  The 
two  shells  illustrated,  sub-figures  21  to  23,  and  sub-figures  36  to  39,  agree  in 
every  feature  except  in  the  size  and  direction  of  their  cardinal  lines. 

Formation  and  Locality.  —  Found  in  the  lower  strata  of  the  Niagara  group,  which  may  possibly 
belong  to  the  Clinton,  in  the  quarries  east  of  the  city  of  Louisville,  Ky.,  where  it  is,  however,  a  rather  rare 
species,  of  which  fair  specimens  are  very  seldom  foumi. 

Genus  Centronella. 

Centronella,  Billings.     Can.  Nat.  and  Geol.,  Vol.  4—1859. 
Etymology  :  a  little  point. 

Shells  having  the  general  form  of  Terebratula.  Dorsal  valve  with  a  loop  con- 
sisting of  two  riband-like  lamellae,  which  extend  about  one-half  the  length  of 
the  shell.  These  lamellae  at  first  curve  gently  outwards,  and  thence  approach 
each  other  gradually,  until  at  their  lower  extremities  they  meet  at  an  acute 
angle  ;  then  becoming  united,  they  are  deflected  backwards  towards  the  beak, 
in  what  appears  to  be  a  thin,  flat,  vertical  plate.  Near  their  origin,  each  bears 
upon  the  ventral  side  a  single  triangular  crural  process.  This  genus  appears  to 
stand  between  Terebratula  and  Waldheimia.  In  the  former  the  loop  is  short, 
not  exceeding  greatly  one-third  the  length  of  the  shell,  and  not  reflected.  In 
the  latter  it  extends  nearly  to  the  front,  and  is  reflected,  but  the  laminae  are 
not  united  until  they  are  folded  back,  (Billings.) 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  153 

Centronella  glans-fagea,    HALL. 

Plate  XXXI.,  figures  14,  15,  16  and  17. 

Rhynchonella  glans-fagea,  Hall.     Tenth  Rep.  on  St.  Cab.,  p.  125 — 1857. 
Cenironella  glans-fagea,  Billings.     Canadian  Nat.  and  Geol.,  p.  131 — 1859. 
Centronella  glans-fagea,  Hall.     Sixteenth  Rep.  on  St.  Cab. — 1863. 
Centronella  glans-fagea,  Hall.     Pal.  H.  Y.,  Vol.  4,  p.  399 — 1867. 

Shell  small,  ovate  or  sub-triangular,  concavo-convex,  with  rounded  base  and 
very  unequal  valves. 

Ventral  valve  much  larger  than  dorsal,  greatly  elevated  in  its  center  line 
from  beak  to  front,  thus  making  the  valve  sub-carinate,  or  its  transverse  section 
triangular.  From  the  sub-carinate  middle  line  it  curves  very  abruptly  to  the 
lateral  margins,  while  longitudinally  there  is  almost  no  curvature  in  the  whole 
valve  except  at  the  umbo;  the  beak  is  much  extended  beyond  that  of  the 
opposite  valve,  and  arched  dorsally  far  enough  to  extend  to  the  level  of  dorsal 
valve. 

Dorsal  valve  sub-angularly  concave  from  beak  to  front,  the  depression  cor- 
responding to  the  angular  elevation  of  the  other  valve ;  the  beak  not  incurving 
into  the  opposite  valve ;  the  mesial  sinus  widening  rapidly  towards  the  front, 
extending  in  the  basal  third  to  the  lateral  margins.  With  the  exception  of 
some  concentric  lines  of  growth,  there  are  no  other  surface-markings.  The 
specimen  illustrated  is  one  of  the  largest  found  in  Kentucky;  it  also  shows  the 
usual  proportion  between  width  and  length.  Comparing  our  shells  of  this 
species  with  Prof.  Hall's  figures,  we  find  them  differ  from  most  of  his  forms  in 
size  and  shape ;  still  they  have  the  specific  aspect  and  characters. 

Formation  and  Locality. — Found  in  the  rotten  hornstone  of  the  Devonian  group  in  Jefferson 
county,  Ky.,  and  Clark  couiity,  Indiana,  where  it  is,  however,  rarely  met  with,  especially  in  well  preserved 
or  even  fair  specimens. 

Genus  Terebratula.    Lihwya. 

Terebratula,  Llhwyd.     Lith.  Brit.  Ichn. — 1696. 
Etymology :  diminutive  of  terebratus,  perforated. 

Types  :  T.  maxillata  and  T.  vitrea. 

Shell  minutely  punctate,  smooth  and  convex,  usually  round  or  oval.  Ven- 
tral valve  with  a  prominent  beak,  which  is  truncated  and  perforated ;  foramen 
circular. 

Dorsal  valve  with  a  depressed  umbo ;  a  prominent  cardinal  process  between 
the  dental  sockets ;  deltidium  of  two  pieces,  frequently  blended ;  loop  very 
short,  simple,  attached  by  its  crura  to  the  hinge-plate, 

GEOL.   SUK. — 20 


154  PALEONTOLOGY    OF    KENTUCKY. 

Terebratula  harmonia.    HALL. 

Plate  XVII.,  figures  1,  2,  3  and  4. 
Terebratula  harmonia,  Hall.     Pal.  H.  Y.,  Vol.  4,  p.  388—1867. 

Shell  of  more  than  medium  size ;  ovate  or  sub-spatulate  ;  tapering  somewhat 
abruptly  to  the  beak,  compressed  at  the  margins,  but  convex  in  middle ;  base 
regularly  curved. 

Ventral  valve  regularly  arcuate  from  beak  to  front,  moderately  convex  in 
the  middle ;  a  little  gibbous  above,  and  depressed  convex  or  slightly  concave 
towards  the  front ;  the  upper  part  narrowing ;  the  beak  much  extended,  atten- 
uate and  arcuate,  but  not  closely  incurved  ;  apex  perforated,  the  slope  to  the 
cardinal  margin  scarcely  concave ;  deltidial  plates  large. 

Dorsal  valve  moderately  convex,  sometimes  a  little  more  prominent  along 
the  middle  in  the  upper  part,  and  depressed  towards  the  front  and  sides. 

Surface  marked  by  fine  concentric  lines  of  growth ;  the  substance  of  the 
shell  finely  punctate. 

This  species  resembles  to  a  certain  degree  Ter.  sullivanti,  but  it  is. more  regu- 
larly arcuate  from  beak  to  front  of  the  ventral  valve,  and  has  a  regularly 
rounded  base,  while  Ter.  sullivanti  has  a  truncate  or  sinuate  front.  Its  well 
marked  regular  form  in  larger  specimens  will  easily  identify  it. 

Formation  and  Locality.— Found  in  the  corniferous  limestone  at  and  around  the  Falls  of  the  Ohio, 
in  Kentucky  and  Indiana.  It  is  a  somewhat  rare  species.  Prof.  Hall  received  the  original  specimens, 
from  which  he  made  his  description  and  illustrations  of  this  species,  from  the  late  Dr.  James  Kiiapp,  who 
collected  the  same  at  the  Falls  of  the  Ohio. 

Terebratula  jucunda.    HALL. 

Terebratula  jucunda,  Hall.     Pal.  N.  Y.,  Vol.  4,  p.  390—1867. 

Shell  of  medium  size ;  sub-circular  or  very  broadly  ovate  ;  length  and  width 
about  equal ;  regularly  rounded  in  the  margins  of  the  basal  half,  but  abruptly 
converging  to  the  ventral  apex  in  upper  half. 

Ventral  valve  moderately  convex ;  gibbous  in  the  umbonal  region,  sloping 
in  a  gentle,  regular  curve  to  the  base  and  baso-lateral  margins,  showing  a  faint 
mesial  depression ;  beak  obtuse  and  arched  over  the  umbo  of  the  opposite 
valve  ;  apex  truncated  by  a  rounded  foramen. 

Dorsal  valve  less  convex  than  the  ventral,  but  regularly  arched  all  over  the 
surface,  with  the  exception  of  the  cardinal  angles,  which  are  somewhat  in- 
flated. The  specimen  before  me  shows  a  faint  elevation  in  the  basal  half, 
corresponding  with  the  sinus  of  opposite  valve. 

Surface  is  marked  by  fine  concentric  striae  or  lines  of  growth.  My  specimen 
measures  in  length  and  width  a  little  more  than  three-eighths  of  an  inch. 

Formation  and  Locality. — Occurs  in  the  corniferous  limestone  in  Jefferson  county,  Kentucky,  and 
in  Clark  county,  Indiana, 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  155 

Terebratula  lincklaeni.    HALL. 

Plate  XVII.,  figures  22,  23  and  24. 

Terebratula  lincklaeni,  Hall.     13th  Regent's  Report — 1860. 
Terebratula  lincklaeni,  var.,  Hall.     Pal.  N.  Y.,  Vol.  4,  p.  418—1867. 

Shell  of  medium  size;  sub-ovate  or  sub  triangular,  with  broadly  curved  or 
slightly  truncated  base ;  moderately  ventricose;  length  somewhat  exceeding 
width. 

Ventral  valve  larger,  and  slightly  more  ventricose  than  the  dorsal ;  greatest 
convexity  at  the  unibo,  from  where  it  slopes  in  a  gentle  regular  curve  to  the 
lateral  and  basal  margins,  but  abruptly  towards  the  cardinal  margins,  whose 
borders  are  somewhat  inflected  ;  the  umbo  is  prominent,  and  the  beak  elevated 
and  incurved  above  the  beak  of  the  other  valve ;  at  the  front  there  is  a  slight 
depression  noticeable,  but  this  feature  is  often  wanting. 

Dorsal  valve  smaller,  and  less  convex  than  the  ventral ;  greatest  convexity 
at  the  umbo,  from  where  it  slopes  in  an  almost  straight,  line  to  the  front,  in  a 
gentle  curve  to  the  lateral  margins  and  abruptly  to  the  cardinal  lines ;  umbo 
moderaetly  prominent,  and  the  beak  strongly  incurved  under  that  of  the 
opposite  valve. 

The  surface  is  covered  with  concentric  lines  of  growth,  some  of  which  are 
more  prominent,  and  divide  the  surface  of  some  individuals  into  different 
zones.  No  other  surface-markings  are  visible  on  our  specimens,  which  are  all 
in  a  silicified  condition. 

Formation  and  Locality. — Found  in  the  rotten  hornstone  of  the  Devonian  formation,  in  Jefferson 
county,  -Ky.,  and  in  Clark  county,  Ind.;  it  is  of  rather  rare  occurrence.  This  species  resembles  Ter.roemin- 
geri,  with  which  it  is  associated,  but  differs  by  having  its  greatest  width  near  the  base,  while  Ter.roemin- 
geri  has  its  maximum  width  above  the  middle,  and  the  latter  species  is  generally  more  gibbous  and  stronger 
umbonated. 

Terebratula  roemingeri.    HALL. 

Plate  XVI.,  figures  20,  21  and  22. 

Terebratula  roemingeri,  Hall.     Sixteenth  Rep.  on  St.  Cab.,  p.  48 — 1863. 
Terebratula  roermngeri,  Hall.     Pal.  N.  Y.,  Vol.  4,  p.  389—1867. 

Shell  ovate,  more  or  less  gibbous  ;  truncate  or  slightly  sinuate  in  front. 

Ventral  valve  gibbous  above  the  middle;  umbo  gibbous,  inflated;  beak  promi- 
nent, incurved  over  that  of  the  opposite  valve,  and  truncated  by  a  round  for- 
amen, which  is  often  mainly  anterior  to  the  apex,  and  completed  on  the  lower 
side  by  two  deltidial  plates ;  cardinal  slopes  rounded,  often  depressed  in  the 
middle  towards  the  front. 

Dorsal  valve  extremely  gibbous,  little  longer  than  wide ;  the  greatest  con- 
vexity at  the  middle  or  above. 


Io6  PALEONTOLOGY    OF    KENTUCKY. 

Surface  marked  by  fine  concentric  lines  of  growth,  which  are  often  crowded 
into  prominent  wrinkles  towards  the  front.  Shell  structure  finely  punctate. 

The  interior  shows  a  short  terebratuliform  loop,  which  is  abruptly  recurved 
at  its  lower  extremities. 

This  species  resembles  Ter.  lincklaeni,  from  which  it  differs,  however,  by  its 
greater  gibbosity,  by  having  its  greatest  width  above  the  middle,  while  that 
species  has  its  maximum  width  near  the  base,  and  by  its  truncated  or  sinuate 
base. 

Formation  and  Locality. — Pound  in  the  rotten  hornstone  of  the  Devonian  formation  in  Jefferson 
county,  Ky.,  and  in  Clark  county,  lud,  A  rather  rare  species. 


MOLLUSCA. 

PTEROPODA. 
Genus  Tentaculites. 

^  Tentaculites,  Schiotheim.     Petrefacten— 1820. 
Etymology :  tentaculum,  a  feeler ;  lithos,  stone.  ] 

The  shells  belonging  to  this  genus  are  easily  distinguished  by  their  exterior 
appearance ;  they  form  very  elongated,  slender  cones,  marked  by  prominent 
annulations  and  fine  transverse  striae. 

The  place  which  these  shells  had  to  occupy  in  the  great  sub-kingdom  Mol- 
lusca,  was  for  a  long  time  doubtful,  until  in  1845  Mr.  Austin  assigned  them  to 
the  Pteropoda,  which  position  is  accepted  by  all  the  naturalists  up  to  the  pres- 
ent day,  though  doubts  are  sometimes  expressed  as  to  their  relation  with  the 
thin  hyaline  shells  of  most  of  the  existing  forms  of  Pteropoda. 

Tentaculites  scalariformis.    HALL. 

Plate  XXXI.,  figure  12. 

Tentaculites  scalaris,  Hall.    Geol.  of  N.  Y.,  4th  Dist.,  p.  172—1843. 
Tent,  scalariformia  and  T.  stcula.  Hall.     Illust.  of  Dev.  Fossils — 1876. 
Tentaculites  scalariformis,  Hall.     Pal.  N.  Y.,  Vol.  6,  pt.  2,  p.  167—1885. 

Shell  elongate-conical,  straight,  somewhat  more  cylindrical  in  approaching 
the  aperture ;  the  apex  in  well  preserved  specimens  extremely  attenuate,  and 
quite  solid  for  one-fourth  to  one-third  of  the  entire  length  of  the  shell.  Annu- 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  157 

lations  prominent,  sub-angular,  sometimes  rounded  on  the  larger  part  of  the 
<-one ;  closely  arranged  and  sharply  angular  near  the  apex,  gradually  increas- 
ing their  distance;  becoming  less  angular  with  the  increase  of  the  size  of  the 
skell  and  obtuse  and  rounded  towards  the  aperture.  On  the  outer  half  of 
th*  shell,  tht-  spaces  between  the  annulations  are  greater  than  the  annulations 
themselves.  The  interspaces,  as  well  as  the  annulations,  are  covered  in  well 
preserved  specimens  with  fine,  even,  transverse  striae;  the  number  of  which 
differ  greatly.  In  some  specimens  there  is  much  irregularity  in  the  distance 
and  development  of  the  annulations  towards  the  aperture.  The  extreme 
point  of  the  apex  is  rarely  or  never  preserved  in  our  specimens. 

Our  specimens  of  this  species  are  always  silicitied,  and  maintain  their  origi- 
nal cylindrical  form  ;  they  never  suffered  compression. 

The  shells  of  this  species  attain  a  length  of  one  inch — rarely  more,  but 
usually  somewhat  less.  The  largest  individual  before  me,  and  of  which  the 
illustration — figure  12,  plate  31 — was  made,  measures  one-half  of  an  inch  ;  the 
figure  is  enlarged  to  double  size. 

Formation  and  Locality. — Found  in  the  rotten  hornstone  of  the  Devonian  formation,  in  Clark 
county,  Indiana,  on  the  northern  shore  of  the  Ohio  river,  opposite  its  falls,  and  in  the  cherty  layers  super- 
imposed upon  the  hydraulic  limestone  at  Watson's  Station,  on  the  Ohio  and  Mississippi  Railroad 

Genus  Styliola    Lesueur. 

Etymology :  stylos,  a  pillar. 

Prof.  Ludwig  gives  the  following  translation  of  a  description  of  this  genus 
from  M.  Barrande :  Shell  small ;  transverse  section  circular ;  closed  below, 
and  thicker  than  in  the  upper  part ;  conical.  Surface  without  annulations ; 
smooth,  but  with  fine  striae  of  growth,  and  sometimes  with  fine  longitudinal 
striae ;  without  longitudinal  slit,  but  sometimes  with  one  or  two  longitudinal 
grooves,  which  do  not  penetrate  the  shell ;  without  operculum,  and  without 
interior  partitions,  but  having  a  persistent  point  sometimes  curved  backward. 
The  greatest  width  is  at  the  opening,  which  is  oblique  or  normal  to  the  axis 
of  shell. 

Styliola  fissurella.    HALL. 

Tentaculites  fissurella.  Hall.     Geol.  Surv  4th  Dist.  N.  Y.— 1843. 
Not.  Tentaculites fissurella,  Hall.     111.  of  Dev.  Fossils— 1876. 
Styhola  fissurella,  Hall.     Pal.  N.  Y.,  Vol.  6,  pt.  2,  p.  178—1885. 

Shell  an  extremely  slender,  elongate  cone.  Apical  portion  of  shell  solid. 
Apex  extremely  minute,  often  bulbiform,  and  very  gradually  enlarging  to  the 
aperture. 

Surface  often  smooth  and  without  any  visible  ornamentation,  so  far  as  can 


158  PALEONTOLOGY  OF  KENTUCKY. 

be  ascertained,  or  with  fine  striae  or  lines  of  growth,  which  are  often  unequally 
developed  on  different  parts  of  the  shell ;  and  also  with  fine  longitudinal 
striae,  which  may  be  present  with  or  without  the  transverse  striae.  Length 
different  in  different  individuals.  Prof.  Hall  gives  their  length  from  two  to 
five  millimeters. 

The  specimens  before  me,  which  have  all  the  characters  mentioned  in  the 
foregoing  description,  are  considerably  larger ;  they  are  only  fragments,  with- 
out apex  and  aperture,  but  all  indications  point  at  least  to  a  length  exceeding 
half  an  inch. 

Formation  and  Locality. — Occurs  in  the  upper  strata  of  the  Devonian  formation,  at  and  around 
the  Fulls  of  the  Ohio,  in  Kentucky  and  Indiana.  This  little  shell  is  rather  rare. 


MOLLUSCA. 

GASTEROPODA. 
Genus  Bellerophon. 

Bellerophon,  Montfort.     Conch.  Syst.,  Vol.  1—1808. 
Etymology :  a  mythological  name. 

The  type  of  this  genus  is  Bellerophon  bicarinatus.  The  shells  of  this  genus 
are  symmetrically  convoluted,  globular  or  discoidal,  strong,  few  whorled ;  the 
whorls  are  often  sculptured ;  dorsally  keeled.  The  apereture  is  sinuated  and 
deeply  notched  on  the  dorsal  side  ;  its  shape  is  variable,  sometimes  triangular, 
and  sometimes  reniform  or  sub-orbicular.  The  surface  is  usually  marked  by 
fine  concentric  striae,  and  sometimes  by  fine  revolving  striae  also. 

This  genus  extends  from  the  Lower  Silurian  to  the  Carboniferous,  inclu- 
sively. 

Bellerophon  leda.    HALL 

Plate  XVII.,  figures  12  and  13. 

Bellerophon  leda,  Hall.     Descpt.  of  New  Sp.  of  Foss.,  p.  30—1861. 
Bellerophon  leda,  Hall.    Fifteenth  Rep.  N   Y  St.  Cab.,  p.  58—1862. 
Bellerophon  leda,  H.  and  W.    29th  Regent's  Rep.,  p.  '200—1872. 
Bellerophon  leda,  H  and  W.     27th  Regent's  Rep.,  pi.  13—1875. 
Bellerophon  leda'QM.     Illust  of  Dev.  Foss.,  pi  24— 1876. 
Bellerophon  leda,  Hall.    Pal.  N.  Y  ,  Vol  5,  pt.  2   p.  110—1879. 

Shell  sub-globose,  often  a  little  flattened  upon  the  dorstim ;  body-whoil 
ventricose,  very  rapidly  expanding ;  aperture  very  wide  ;  peristome  abruptly 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  159 

spreading,  broadly  sinuate  in  front,  and  sometimes  with  a  deep  notch  in  the 
middle.  The  margin  gently  recurved,  joining  the  volution  a  little  on  the 
ventral  side  where  it  is  thickened,  somewhat  abruptly  curving  over  and  partly 
inclosing  the  small  umbilicus,  and  extending  in  a  callus  over  the  columellar 
lip,  which  is  sometimes  distinctly  striato-pustulose. 

Surface  marked  by  strong  longitudinal  or  revolving  striae,  which  alternate 
in  size ;  are  sometimes  fasciculate,  and  often  finer  and  more  numerous  on  each 
side  of  the  dorsal  band  than  on  the  lateral  portions  of  the  shell.  The  revolv 
ing  striae  are  cancellated  by  finer,  sub-equal,  thread-like,  transverse  striae. 
The  dorsal  band  is  narrow,  rarely  elevated,  or  sometimes  scarcely  raised  above 
the  surface,  and  usually  flat  or  slightly  concave  ;  the  concentric  striae  making 
an  abrupt  retrorse  curve  upon  it  in  crossing.  The  band  is  likewise  usually 
marked  by  two,  three  or  more  revolving  striae,  finer  than  those  on  the  sides  of 
the  shell,  and  sometimes  quite  obscure. 

This  species  is  very  variable  in  size  and  form  as  well  as  in  surface-markings, 
which  are,  however,  mainly  due  to  the  distortion  of  the  shell.  A  specimen 
without  distortion  is  a  very  rare  occurrence.  The  average  size  of  this  shell  is 
about  three-fourths  of  an  inch.  The  specimens  found  in  our  rocks  seldom 
exceed  the  one  illustrated  on  our  plate. 

Formation  and  Locality. — Occurs  in  the  rotten  hornstone  of  the  upper  strata  of  the  Devonian  for- 
mation, in  Jefferson  county,  Ky ,  and  in  Clark  county,  Ind.,  where  it  is  not  rare,  but  fair  specimens  are 
seldom  found. 

Genus  Bucania.    Han. 

Bucania,  Hall      Pal  N.  Y.,  Vol.  1-4847. 
Etymology .  bukane,  a  trumpet. 

Shells  convolute ;  spire  equally  concave  on  either  side  ;  volutions  in  the  same 
plane,  all  visible,  outer  one  ventricose,  inner  ones  usually  angulated  on  the 
edge,  concave  on  the  ventral  side ;  aperture  rounded  oval,  somewhat  com- 
pressed on  the  inner  side  by  contact  with  the  next  volution,  laterally  and  dor- 
sally  abruptly  expanded. 

This  genus  is  established  for  the  reception  of  several  species  of  shells  of  a 
peculiar  form,  which  were  formerly  placed  with  the  Bellerophons,  but  from 
which  they  differ  by  having  all  their  volutions  visible,  which  is  not  the  case  in 
Bellerophon  proper.  Bucania  differs  from  Porcella  in  being  symmetrical,  the 
volutions  in  the  same  axis  being  equally  expanded  on  either  side,  both  sides 
presenting  the  same  aspect,  and  the  aperture  corresponding  to  the  axis  of  the 
shell. 


160  PALAEONTOLOGY    OF    KENTUCKY. 

Bucania  devonica.     HALL  AND  WHITFIELD. 

Plate  XXVI.,  figure  9,  and  Plate  XXII.,  figures  3  and  4. 
Bucania  devonica,  H.  and  W.     24th  Regent's  Kep.,  p.  195 — 1872. 
Bucania  devonica,  H.  and  W.     27th  Kegent's  Rep.,  pi.  13 — 1875. 

Shell  discoid,  widely  and  equally  umbilicate  on  the  two  sides ;  remaining 
volutions  about  four ;  slightly  embracing,  vertically  compressed,  giving  the 
transverse  diameter  a  little  more  than  twice  the  vertical  diameter.  Lateral 
margins  of  the  volutions  obtusely  angular  towards  the  dorsal  side. 

The  surface  has  apparently  been  marked  by  several  (three  or  four)  revolving 
ridges  or  carina  on  each  side  of  the  center  or  dorsum,  which  is  greatly  concave. 
Finer  surf  ace- markings,  and  also  the  form  and  size  of  tjie  aperture,  are  un- 
known. 

Formation  and  Locality. — Occurs  in  the  Corniferous  rock  of  the  Devonian  formation  in  Jefferson 
county,  Ky.,  and  in  Clark  county,  Ind.  It  is  always  found  in  an  exfoliated  condition  as  internal  casts, 
which  seldom  show  any  surface-markings  at  all, 

Genus  Platyceras.    conrad, 

Plaiyceras,  Conrad.     Ann.  Geol.  Rep.  of  N.  Y. — 1840. 

Etymology  ;  platys,  broad ;  keras,  a  horn. 

Copied  from  Hall's  Pal.  N.  Y,,  Vol.  3,  page  309—1859. 

Shell  depressed  sub-globose,  sub  ovoid  or  obliquely  sub-conical.  Spire  small, 
volutions  few,  sometimes  free  and  sometimes  contiguous,  without  columella. 
Aperture  more  or  less  expanded,  often  companulate,  and  sometimes  with  the 
lip  reflected.  Peristome  entire  or  sinuous. 

Surface  striated  or  cancellated,  often  spirally  ridged  or  plicated,  and  some- 
times strongly  lamellose  transversely,  nodose  or  spiniferous. 

Platyceras  bucculentum.    HALL. 

Plate  XXIII.,  figures  9  and  11,  and  Plate  XXV,,  figure  8. 
Platyceras  bucculentum.  Hall.     Desc,  of  New  Sp  of  Foss ,  p.  6 — 1861. 
Platyceras  bucculentum,  Hall      15th  Regent's  Rep,  p.  33 — 1862. 
Platyceras  bucculentum,  Hall,     lllust  of  Dev.  Fossils,  pi.  3 — 1876.  v 

Platyceras  bucculentum,  Hall.     Pal.  N.  Y.,  Vol.  6,  pt.  2,  p.  10—1885. 

Shell  ventricose,  obliquely  sub-ovoid ;  apex  extremely  attenuate,  the  spire 
making  one  or  two  closely  enrolled  volutions,  with  a  gently  enlarging  diameter, 
and  below  this  abruptly  expanding;  very  ventricose  in  the  middle  and  lower 
part,  spreading  more  upon  the  right  side  than  upon  the  left.  The  shell  near 
the  posterior  side  swells  out  into  a  distinct  pouch-like  projection,  with  two  or 
three  rounded  folds  or  semi-plications,  which  give  a  deeply  sinuous  outline  to 
the  margin.  Aperture  sub- ovate  and  sinuate  on  the  right  posterior  side.  Per- 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  161 

istome  sinuous,  and  on  the  posterior  side  spreading  partially  over  the  preceding 
volution. 

Surface  marked  by  fine,  closely  arranged  concentric  striae,  which  are  undu- 
lated towards  the  margin  of  the  aperture,  and  sometimes  over  the  greater  part 
of  the  surface,  the  irregularity  having  commenced  during  the  earlier  stage  of 
growth.  In  well  preserved  specimens  there  are  revolving  striae  or  fascicles, 
rising  in  little  bands  of  obsolescent  striae,  giving  a  waved  aspect  to  the  sur- 
face. 

This  species  resembles  somewhat  P.  ventricosum,  of  the  lower  Helderberg 
group,  but  the  first  volution  is  more  slender,  the  spire  less  closely  enrolled, 
while  the  pouch-like  expansion  and  the  revolving  bands  are  distinctive  fea- 
tures. In  size  it  differs  greatly  in  different  specimens,  as  may  be  noticed  in  the 
different  figures. 

Formation  and  Locality — Occurs  in  the  Corniferous  limestone  of  the  Devonian  formation  in 
Jefferson  county,  J£y,,  and  in  Clark  county,  Ind. 

Platyceras  conicum.    HALL. 

Plate  XXV.,  figures  2  and  11.  • 

Platyceras  conicum,  Hall.     Descript.  of  New  Foss.,  p.  3 — 1861. 
Platyceras  conicum,  Hall.     15th  Keg.  Report,  p.  31 — 1862. 
Platyceraa  conicum,  Hall.     Illust.  Devon.  Fossils — 1876. 
Platyceras  conicum,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  2,  p.  3—1885. 

Shell  above  medium  size,  erect  conical,  the  minute  apex  closely  incurved 
but  mostly  missing,  at  least  in  the  specimens  found  in  our  rocks.  Body- 
chamber  entirely  straight,  with  broad,  undefined,  longitudinal  ridges  and 
depressions,  which  are  faint  or  obsolete  at  or  near  the  apex,  but  become  more 
distinct  approaching  the  aperture.  The  height  of  the  shell  is  usually  greater 
than  the  width  of  the  aperture,  which  is  somewhat  elliptical  in  shape ;  its 
length  exceeding  its  width. 

The  surface  is  covered  by  concentric  undulating  striae,  which  become  sub- 
lamellose  towards  the  aperture,  and  are  sometimes  closely  crowded  and 
wrinkled  with  numerous  knots  or  nodes.  Peristome  deeply  sinuous.  The 
length  of  the  shell  varies  in  different  specimens,  and  can  not  be  exactly  as- 
certained on  account  of  the  missing  apex;  but  it  is  certain  that  the  shell 
illustrated  in  figure  11,  plate  25,  if  complete,  would  certainly  measure  not  less 
than  two  inches  and  a  quarter. 

This  species  resembles  P.  pyramidatum  of  the  Lower  Helderberg  group,  but 
is  less  elongate  ;  the  peristome  more  sinuous,  and  the  longitudinal  ridges  and 
depressions  are  more  distinct;  besides,  the  crowded,  wrinkled  and  nodose  striae 
of  our  shell  are  missing  in  the  Silurian  species. 

Formation  and  Locality. — Occurs  in  the  Corniferous  limestone  of  the  Devonian  formation   at  the 
Falls  of  the  Ohio,  on  the  Kentucky  side  of  the  river,  and  in  different  other  places  in  Jefferson  county,  Ky., 
and  Clark  county,  Ind.     It  is  not  very  rare,  but  fair  specimens  are  not  abundant. 
OEOL.  SUR. — 21 


162  PALAEONTOLOGY    OF    KENTUCKY. 

Platyceras  compressum.    N.  SP. 

Plate  XXV.,  figures  8  and  9. 

Shell  of  medium  size  or  below  it ;  very  compressed  in  a  lateral  direction. 
Apex  closely  enrolled  for  one  or  one  and  a  half  volutions,  which  increase  in 
size  very  gently  ;  after  this  the  body-whorl,  measuring  a  little  more  than  a  half 
volution,  expands  very  rapidly  in  the  post  anterior  direction,  while  its  lateral 
extension  remains  almost  the  same  throughout  the  whole  length  of  the  body 
volution.  The  right  side  of  the  shell  is  moderately  convex  in  the  apical  half, 
but  becomes  concave  in  the  lower  half,  the  center  line  of  the  concavity  running 
at  right-angles  to  the  peristome.  The  left  side  is  throughout  concave,  but  the 
center  line  of  the  concavity  is  parallel  to  the  peristome,  or  at  least  nearly  so. 
The  aperture  is  very  elongate  and  narrow,  and  expands  more  or  less  at  the 
posterior  end  of  its  right  side.  The  surface  is  marked  by  fine  concentric  lamel- 
lose  striae,  which  are  closely  arranged,  especially  in  the  lower  half,  and  by 
somewhat  obscure,  shallow,  radiating  plications,  only  noticed  in  the  lower 
part. 

A  smaller  specimen,  of  about  half  the  size  of  the  one  illustrated,  does  not 
show  any  indications  of  those  plications.  The  size  of  the  larger  specimen  is 
shown  in  figures  8  and  9,  on  plate  25. 

Formation  and  Locality. — This  beautiful  little  shell  was  loaned  to  me  for  description  and  illustra- 
tion by  Major  Wm.  J.  Davis,  who  found  it  at  the  Falls  of  the  Ohio,  in  the  Corniferous  limestone,  imbedded 
in  the  rock,  which  he  removed,  without  the  least  injury  to  the  shell,  by  the  use  of  muriatic  acid  and  para- 
fine.  The  smaller  specimen  he  found  in  the  same  strata,  but  already  weathered  out,  in  Clark  county 
Indiana. 

Platyceras  dumosum.     CONRAD. 

Plate  XXIII.,  figures  1  to  6  and  12. 

Platyceras  dumosum,  Conrad.     Third  Ann.  Kep.  of  4th  Dist.  N.  Y. — 1840. 
Platyceras  dumosum,  Hall.     12th  Kegent's  Report,  p.  19 — 1859. 
Platyceras  dumosum,  Hall.     Descript.  of  New  Spec,  of  Fossils — 1861. 
Platyceras  dumosum,  Hall.     15th  Regent's  Report,  page  37 — 1862. 
Platyceras  dumosum,  Hall.     Illust.  of  Dev.  Foss.,  pis.  5  and  6 — 1876. 
Platyceras  dumosum,  Hall.     Pal.  N.  Y.,  Vol.  6,  pt.  2,  page  14—1885. 

Shell  above  medium  size ;  sub-ovoid ;  extremely  ventricose  in  full  grown 
specimens.  Its  length,  from  the  apex  to  the  anterior  margin  of  the  aperture, 
greater  than  the  height.  Apex  minute,  closely  enrolled  for  a  single  volution 
or  more,  then  the  body-whorl  becomes  free  and  rapidly  expanded,  spreading 
more  upon  the  right  side,  which  is  sometimes  depressed-convex,  while  the  left 
side  is  more  abruptly  rounded.  The  aperture  is  sub-rhomboid-ovate,  with 
the  peristome  making  a  sinus  on  the  left  side,  the  posterior  margin  widely 
separated  from  the  preceding  volution. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  163 

The  surface  is  marked  by  strong  concentric  striae,  which  are  interrupted  and 
irregular  from  the  numerous  nodes  projecting  from  the  shell,  and  extended 
into  long  tubular  spines. 

This  shell,  in  full  grown  specimens,  attains  sometimes  a  length  of  two  inches 
and  a  half,  and  its  entire  surface  is  covered  with  strong,  tubular  spines,  which 
are  sometimes  two  inches  long,  as  may  be  seen  in  the  inclosing  rock.  In  the 
specimen  figured  on  plate  23,  figure  2,  all  the  spines  are  preserved  to  a  certain 
extent ;  some  measure  more  than  half  an  inch.  These  shells  were  found  at  the 
falls,  imbedded  in  soft  limestone  ;  the  shells  themselves  were  entirely  silicified. 
By  the  use  of  muriatic  acid,  the  limestone  envelope  was  gradually  removed, 
and  any  portion  of  the  shell  or  spines,  whenever  it  was  sufficiently  freed  from 
the  matrix,  was  then  carefully  coated  with  paraffine,  to  prevent  the  acid  from 
further  acting  upon  these  cleared  portions.  By  this  process,  in  which  very 
diluted  acid  must  be  used,  and  which  requires  often  several  days  close  watch- 
ing, in  order  to  protect  the  exposed  parts  in  time  from  the  further  action  of 
the  acid,  the  most  excellent  specimens  in  shells,  crinoids,  and  especially  in 
coral,  are  obtained.  In  the  collection  of  my  co-laborer  and  friend,  Major  Wm. 
J.  Davis,  the  author  of  "Kentucky  Fossil  Corals,"  the  most  exquisite  and 
valuable  specimens  of  which  that  cabinet  is  so  rich,  and,  therefore,  unparalleled 
by  any  other  collection  in  this  country,  are  produced  by  the  careful  application 
of  muriatic  acid  and  paraffine.  The  specimens  of  this  species,  found  in  the 
clay,  are  mostly  exfoliated,  and  show  the  places  of  the  spines  by  moderately 
elevated  nodules,  as  may  be  seen  in  the  figures  5,  6  and  12 ;  the  last  one  is  that 
of  a  young  specimen. 

Formation  and  Locality. — Occurs  in  the  upper  strata  of  the  Corniferous  limestone,  just  above  the 
hydraulic  cement  rock,  at  the  Falls  of  the  Ohio,  on  the  Kentucky  side  of  the  river;  the  layers  containing 
them  are  only  exposed  at  a  very  low  stand  of  the  river.  In  the  clay,  exfoliated  shells  are  found  in  differ- 
ent places  in  Jefferson  county,  Ky.,  and  in  Clark  county,  Ind. 

Platyceras  dumosum,  var.  rarispinum.    HALL. 

Plate  XXIII.,  figures  7  and  8. 

Platyc.  dumosum,  var.  rarispinum.  Hall.     Desc.  of  New  Sp.  of   Foss. — 1861. 
Platyc.  dumosum,  var.  rarispinum,  Hall.     15th  Reg.  Rep.,  p.  38 — 1862. 
Platyc.  dumosum,  var.  rarispinum,  Hall.     Illust.  of  Dev.  Foss.,  pi.  5 — 1876. 
Plat,  dumosum,  var.  rarispinum,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  2,  p.  16 — 1885. 

Shell  only  of  medium  size  or  below  it ;  sub-ovate  ;  apex  closely  incurved 
and  enrolled  for  about  one  and  one-half  volutions,  and  in  some  shells  the  volu- 
tions are  contiguous  nearly  to  the  aperture,  as  seen  in  figure  8,  plate  23.  For 
one  volution  and  a  half  or  three-fourths  the  shell  is  slender  and  only  gently 
enlarging  ;  after  that  the  body- whorl  expands  more  rapidly  and  becomes  mod- 
erately ventricose,  depressed  on  the  dorsum,  and  the  left  side  sometimes 


164  PALEONTOLOGY    OF    KENTUCKY. 

marked  by  a  strong  fold,  indicating  a  sinus  in  the  margin  of  the  peristome 
commencing  at  an  early  stage  of  growth.  Aperture  somewhat  oval,  longest 
in  the  dorsal-ventral  axis. 

Surface  marked  by  wrinkled,  concentric  striae,  which  are  strongly  undulated 
at  the  base  of  the  spines,  and  often  abruptly  bent  backward  at  other  places. 
Spines  scattered,  comparatively  strong  and  few  in  number,  from  five  to  fifteen 
on  the  whole  shell.  The  specimen  before  me,  a  most  perfect  one,  with  the 
exception  of  a  few  broken  spines,  is  a  complete  hollow  shell  from  apex  to 
aperture,  without  defect ;  it  shows  eleven  spines. 

Formation  and  Locality. — This  shell  was  presented  to  me  by  Major  Win.  J.  Davis,  who  found  it 
in  the  upper  strata  of  the  Devonian  formation,  in  Clark  county,  Indiana.  I  have  no  doubt  that  this  shell 
is  related  to  P.  dumosum,  but  it  differs  sufficiently  from  it  to  constitute  a  distinct  species,"and  not  merely 
a  variety.  It  is  certainly  as  far  removed  from  P.  dumosum  as  P.  multispinosum,  and  if  that  is  considered 
a  good  species,  I  think  our  shell  has  the  same  claim.  It  ought  to  be  called  simply  Platyceras  rarispinum. 
It  differs  by  the  smaller  number  of  spines,  and  by  its  different  shape  from  P.  dumosum,  and  besides,  it  is 
never  found  with  the  latter  in  the  same  strata,  but  occupies  a  higher  horizon. 

Platyceras  echinatum.    HALL. 

Plate  XXXI.,  figure  21. 

Platyceras  echinatum,  Hall.     Descript.  of  Xew  Foss. — 1861. 
Platyceras  echinatum,  Hall.     15th  Kep.  N.  Y.  St.  Cab.— 1862. 
Platyceras  echinatum,  Hall.     Illust.  of  Dev.  Fossils — 1876. 
Platyceras  echinatum,  Hall.    Pal.  N.  Y.,  Vol.  5,  pt.  2,  p.  13—1885. 

Shell  small ;  apex  closely  incurved  for  about  one  and  one-half  volution ;  the 
body-whorl  occupying  about  one  volution,  very  ventricose  ;  rapidly  expanding 
from  the  first  volution,  giving  the  shell  an  obliquely  conical  form.  Aperture 
nearly  circular  or  broad  oval ;  peristome  sinuate ;  the  lines  of  growth  and  fine 
striae  conforming  in  direction  to  the  outline  of  the  margin.  Remains  of 
revolving  lines  are  sometimes  traceable  when  the  shell  is  not  exfoliated. 
Besides  the  concentric  and  obscure  revolving  striae,  the  surface  is  studded 
with  numerous  nodes  or  fine  spines,  which  are  as  much  crowded  as  the  figure 
21,  plate  31,  shows,  but  they  are  not  quite  so  regularly  arranged  as  in  the 
illustration.  The  specimen  before  me  has  preserved  the  shell,  but  of  the 
spines  only  short  stumps  are  visible ;  the  spines  perished  by  the  process  of 
silicification.  In  regard  to  size,  this  species  varies  from  half  an  inch  to  an 
inch  and  a  quarter  in  length,  and  in  large  specimens  the  greatest  diameter 
of  the  aperture  is  one  inch.  This  form  could  be  the  young  of  P.  dumosum, 
and  would  probably  be  considered  as  such  if  it  occurred  with  that  species  in  the 
same  strata  or  horizon,  but  this  is  not  the  case.  It  is  never  found  associated 
with  P.  dumosum,  but  occurs  at  a  much  higher  horizon,  and  for  that  reason 
must  be  considered  as  a  distinct  species. 

Formation  and  Locality. — Found  in  the  upper  strata  of  the  Devonian  formation,  in  Clark  county, 
Indiana.  It  is  not  often  met  with. 


FOSSILS    OF    THE    SILURIAN    ANL>    DEVONIAN    ROCKS.  165 

Platyceras  erectum,    HALL. 

Acroculia  erecta,  Hall.     Geol.  Surv.  of  4th  Dist.  of  N.  Y.— 1843. 
Platyceras  erectum,  Hall.     Desc.  of  New  Sp.  of  Foss.,  p.  4 — 1861. 
Platyceras  erectum,  Hall.     15th  Regent's  Report,  p.  4 — 1862. 
Platyceras  erectum,  Hall,     lllust.  of  Devon.  Fossils,  pi.  2 — 1876. 
Platyceras  erectum,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  2,  p.  5—1885. 

Shell  erect  and  slender.  The  spire  at  the  apex  is  closely  enrolled,  for  about 
one  volution  and  a  half,  beyond  which  the  body-volution  becomes  somewhat 
rapidly  expanding,  with  the  aperture  often  spreading.  The  specimens  are 
often  more  arcuate  than  their  name  indicates.  The  aperture  is  oblique,  with 
the  peristome  sinuate. 

The  surface  is  marked  by  closely  arranged,  revolving,  lamellose  striae,  which, 
upon  the  lower  half  of  the  body- volution,  are  abruptly  arched  along  narrow 
bands,  corresponding  with  former  sinuosities  of  the  aperture. 

Formation  "and  Locality. — Occurs  in  the  Corniferous  limestone  of  the  Devonian  formation,  at  the 
Falls  of  the  Ohio,  on  Kentucky  shore  of  river. 

Platyceras  milleri.    N.  SP. 

Plate  XXV.,  figure  1. 

Shell  very  elongate,  forming  a  slender  cone.  Apex  very  minute,  and  closely 
incurved  for  about  one  or  one  and  a  half  volution;  after  this  the  shell  is  free 
for  about  one  and  one-half  volution.  The  whole  shell  increases  very  gradu- 
ally in  size  from  apex  to  aperture.  The  different  volutions  are  separated 
from  each  other  by  very  large  interspaces.  The  aperture  is  nearly  circular, 
and  the  lip  is  entire  without  sinus,  but  with  very  slight  undulations.  The  real 
shell  is  very  thin.  The  surface  is  marked  by  fine,  undulating  concentric  striae 
or  lines  of  growth,  and,  in  well  preserved  specimens,  with  numerous  slender, 
tubular  spines,  which  are  seen  when  part  of  the  matrix  remains  attached  to 
the  shell.  To  a  specimen  of  that  kind  before  me  are  spines  attached  which 
measure  more  than  three-fourths  of  an  inch  in  length. 

This  species  resembles,  in  regard  to  the  number  and  size  of  the  spines, 
Platyceras  dumosum,  but  its  elongated  form  distinguishes  it  from  that  species 
at  the  first  glance.  There  is,  in  fact,  no  other  species  of  Platyceras  known  to 
me  with  which  this  one  might  be  compared. 

Formation  and  Locality. — I  found  three  very  fine  specimens  of  this  species  in  the  Corniferous 
limestone  of  the  Devonian  formation,  at  the  Falls  of  the  Ohio,  on  the  Kentucky  side  of  the  river. 

It  affords  me  great  pleasure  to  name  this  elegant  fossil  In  honor  of  S.  A.  Miller,  Esq.,  of  Cincinnati, 
Ohio.  There  are  very  few  palaeontologists  in  this  country  whose  labors  are  of  equal  importance  with  those 
o '  8.  A.  Miller.  His  catalogue  of  fossils  is  an  invaluable  guide  to  all  his  co-laborers. 


166  PALEONTOLOGY    OF    KENTUCKY 

Platyceras  multispinosum.    MEEK. 

Plate  XXV.,  figure  4. 

Platyceras  multispinosum,  Meek.     Proc.  Acad.  Nat.  Sci.  Phil. — 1871. 
Paiyceras  multispinosum,  Meek.     Pal  of  Ohio,  Vol.  1,  page  210 — 1873. 

Shell  attaining  a  large  size,  considerably  larger  than  its  near  relative,  the  P. 
dumosum ;  it  has  a  very  thin  shell,  is  depressed  sub-ovate  and  very  oblique. 
Its  apex  is  free  in  the  casts — may  not  be  so  in  the  perfect  shell ;  comparatively 
stout,  and  obliquely  coiled  for  about  one  and  one-half  volution ;  after  this  the 
body-whorl  expands  very  rapidly  to  the  aperture,  occupying  in  this  part  of 
the  shell  less  than  half  a  volution. 

Aperture  very  large  and  nearly  round ;  lip  entire  ;  neither  sinus  nor  undu- 
lated. 

Surface  without  any  surface-markings  except  the  numerous  closely  arranged, 
slender,  tubular  spines  on  well  preserved  shells,  or  their  small,  depressed, 
smooth,  undefined  tubercles  or  nodules  on  the  internal  casts.  In  regard  to 
general  size,  and  the  proportion  of  its  different  dimensions,  this  shell  differs 
greatly.  The  illustration,  figure  4,  on  plate  25,  shows  a  large-sized  specimen. 
This  species  differs  from  Platyceras  dumosum  by  its  considerably  larger  size, 
its  more  oblique,  depressed  and  more  rapidly  expanding  form,  and  mainly  by 
its  more  numerous  and  more  slender  spines.  Specimens  belonging  to  this 
species  will  be  very  seldom  confounded  with  P.  dumosum ;  their  difference 
is  noticed  at  the  first  glance,  whether  they  are  shells  or  internal  casts.  The 
spines  are  seldom  attached  to  the  specimens  ;  they  become  separated  by  exfoli- 
ation,  but  are  often  preserved  in  the  matrix. 

Formation  and  Locality- — Occurs  in  the  Corniferous  limestone  of  the  Devonian  formation  at  the 
Falls  of  the  Ohio,  and  in  other  places  in  Jefferson  county,  Ky.,  and  Clark  county,  Ind.  It  is  not  rare, 
though  fair  specimens  are  not  abundant. 

Platyceras  rictum.    HALL. 

Platyceras  rictum,  Hall.  Desc.  New  Sp.  of  Poss  ,  p.  7 — 1861. 

Platyceras  rictum,  Hall.  15th  Regent's  Rep.,  p.  35 — 1862. 

Platyceras  rictum,  Hall.  Illust.  of  Dev.  Fossils,  pi.  4 — 1876. 

Platyceras  rictum,  Hall.  Pal.  N.  Y.,  Vol.  5,  pt.  2,  p.  13—1885. 

Shell  very  depressed,  arcuate  or  sometimes  obliquely  sub-conical;  width 
equalling  and  often  exceeding  height.  Apex  or  nucleus  minute,  the  spire 
enrolled  for  about  one  turn  and  a  half,  when  it  abruptly  expands,  spreading 
more  upon  the  right  posterior  side,  and  becoming  greatly  extended  and  ex- 
panded in  front. 

The  dorsal  line  of  the  first  volution  is  continued  in  an  oblique  angular  ridge, 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  167 

extending  on  the  left  side,  and  often  reaching  to  the  front  of  the  shell,  giving 
a  peculiar  obliquity  to  the  form.  Aperture  expanded,  obliquely  ovate  ;  peris- 
tome  entire,  or  with  a  slight  sinuosity  on  the  left  posterior  side,  and  sometimes 
showing  the  effect  of  the  undefined  folds  of  the  posterior  margin  usually  con- 
tiguous to  the  preceding  volution. 

Surface  marked  by  undulating  concentric  striae,  and  a  few  broad  undulations 
longitudinally.  Aperture  a  little  greater  in  the  diameter  from  front  to  rear 
than  in  the  lateral  one.  Height  reaching  sometimes  to  an  inch  and  a  quarter. 

Formation  and  Locality. — Occurs  in  the  Coruiferous  limestone  of  the  Devonian  formation  in  Jeffer- 
son county,  Ky.,  and  in  ClurU  county,  Ind. 

Platyceras  symmetricum.    HALL. 

Plate  XXIII.,  figure  10. 

Platyceras  symmetricum,  Hall.    Desc.  of  New  Sp.  of  Foss.,  p.  6—1861. 
Platyceras  symmetricum,  Hall.     15th  Eeg.  Kep.,  p.  34 — 1862.  t 
Platyceras  symmetricum,  Hall.     Illust.  of  Dev.  Fossils,  pi.  3 — 1876. 
Platyceras  symmetricum,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  2,  p.  9—1885. 

Shell  elongate,  sub-ovoid,  arcuate,  incurved  nearly  in  the  same  plane ;  apex 
minute,  making  about  one  or  one  and  a  half  volution  before  the  body-whorl 
becomes  free  and  rapidly  or  somewhat  abruptly  expanded ;  spreading  about 
equally  on  the  two  sides  of  the  dorsum,  which  is  more  prominent  and  some- 
times marked  by  a  ridge.  Aperture  oblique,  sub-quadrate  or  rhomboidal ; 
margin  of  the  peristome  sinuate,  and  on  the  posterior  side  distant  from  the 
spire. 

Surface  marked  by  concentric  undulating  striae,  and  longitudinally  by 
obscure  interrupted  ridges,  which,  on  some  parts  of  the  older  shells,  become 
regular  and  uniform,  with  a  narrow  groove  between. 

This  species  is  well  marked  by  the  equilateral  expansion  on  each  side  of  the 
dorsum,  and  by  the  volution  of  the  apex  being  nearly  in  the  same  plane.  The 
posterior  margin  of  the  aperture  is  widely  separated  from  the  preceding  volu- 
tion. The  longitudinal  ridges  are  strongly  marked,  and  of  a  different  char- 
acter from  those  of  characteristic  specimens  of  Plat,  bucculentum ;  it  is  not, 
however,  improbable  that  we  may  find  intermediate  forms  uniting  the  two 
species.  It  is  also  possible  that  a  comparison  of  a  larger  number  of  specimens 
may  prove  that  the  forms  included  under  P.  thetis,  symmetricum  and  buccu- 
lentum, are  only  varieties  of  one  and  the  same  species. 

Formation  and  Locality. — Occurs  in  the  Corniferous  limestone  of  the  Devonian  formation  at  the 
Falls  of  the  Ohio,  and  in  different  other  places  of  Jefferson  county,  Ky.,  and  of  Clark  county,  Ind.,  where 
it  is  usually  found  already  weathered  put  and  entirely  silicified. 


168  PALAEONTOLOGY    OF    KENTUCKY. 

Platyceras  thetis.    HALL. 

Platyceras  thetis,  Hall.  Desc.  of  New  Foss.,  page  4—1861. 

Platyceras  thetis,  Hall.  15th  Kegent's  Rep.,  p.  32—1862. 

Platyceras  thelis,  Hall.  Illust.  of  Dev.  Foss.,  pi.  3—1876. 

Platyceras  thetis,  Hall.  Pal.  N.  Y.,  Vol.  5,  pt.  2,  p.  8—1885. 

Shell  oblique  arcuate  from  base,  with  the  apex  incurved,  nucleus  making 
barely  more  than  a  single  minute  volution ;  gradually  expanding  from  the 
apex  to  near  aperture,  which  is  sometimes  more  abruptly  spreading.  The 
beak  of  the  body- whorl  is  prominent,  and  a  little  flattened  on  the  left  side, 
while  right  side,  from  one-third  to  one-half  the  length,  is  sometimes  marked 
by  two  or  three  longitudinal  folds,  and  often  by  more  numerous,  finer  plica- 
tions. Aperture  a  little  oblique,  nearly  round  or  sub-quadrate,  with  the  peris- 
tome  sinuous. 

Surface  marked  by  line,  closely  arranged  lamellose  striae,  which  are  abruptly 
undulated  on  all  parts  of  the  body  of  the  shell.  This  species  resembles  P. 
attenuatum,  but  differs  in  being  arcuate  from  apex  to  base,  in  the  gradual 
attenuation  towards  the  apex  ,  and  the  closely  incurved  nucleus  and  less  abrupt 
expansion. 

Formation  and  Locality. — Occurs  iii  the  Comiferous  limestone  of  the  Devonian  formation  at  the 
Falls  of  the  Oiuo,  uii  Uiu  JieiUucky  side  of  the  river, 

Platyceras  unguiforme.    HALL. 

Platyceras  unguiforme,  Hall.     Pal.  N.  Y.,  Vol.  3,  p.  322—1859. 

Shell  oblique,  arcuate,  sub-spiral ;  volutions  one  or  two,  more  or  less  con- 
tiguous at  the  apex  ;  last  volution  angular,  extending  in  a  straight  or  slightly 
curved  direction  towards  the  aperture.  Aperture  oblique,  sub-ovoid;  peris- 
tome  sinuous' 

Surface  longitudinally  plicate,  and  marked  by  fine,  crowded,  undulating 
lamellose  striae.  The  plications  are  of  unequal  size;  they  are  flat  and  broad 
on  the  dorsal  side,  and  angular  and  smaller  on  the  ventral  side.  These  plica- 
tions increase  in  number  by  bifurcation. 

Formation  and  Locality. — Found  in  the  Niagara  limestone  in  the  quarries  east  of  the  city  of  Louis- 
ville, Ky.  It  is  a  rather  rare  shell. 

Platyceras  ventricosum.    CONBAD. 

Plate  XXV.,  figure  10. 

Platyceras  ventricosum,  Conrad.     Ann.  Rep.  N.  Y. — 1840. 
Platyceras  ventricosum,  Meek  and  Worthen.     111.  Geol.  Rep.,  Vol.  3 — 1868. 

Shell  obliquely  sub-ovate  ;  composed  of  two  and  a  half  to  three  very  rapidly 
enlarging  contiguous,  volutions,  the  last  one  of  which  is  very  large  and  ven- 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  169 

tricose ;  spire  depressed  below  the  upper  side  of  the  body-whorl.  Aperture 
very  large  and  circular ;  inner  lip  usually  in  contact  with  the  spire,  so  as  to 
leave  a  moderately  large  umbilical  cavity.  Surface  traversed  by  fine  striae, 
and  near  the  aperture  coarser,  somewhat  undulated  lines  of  growth,  crossed  by 
faint  traces  of  extremely  fine,  revolving  lines.  General  size  differs  in  different 
individuals  ;  the  illustration  shows  a  specimen  of  average  size. 

Formation  and  Locality. — Found  in    the  Corniferous   limestone  of    the   Devonian   formation  in 
Jefferson  county,  Ky.,  and  in  Clark  county,  Ind. 


D'Archiac  and  DeVemeuil. 

Murchisonia,  D'Archiac  and  Verneuil.     Bull.  Soc.  Geol.  Fr.,  Vol.  12 — 1841. 
Etymology :  Named  after  Sir  R.  I.  Hurchison,  of  England. 

This  genus  was  proposed  by  D'Archiac  and  De  Verneuil,  to  include  Buccin- 
uni  spinosum  and  B.  abbreviatum  of  Sowerby,  Turritella  bilineata  of  Gfoldfuss, 
and  others.  Shells  spiral,  with  very  elevated  spire  and  many  volutions, 
marked  by  a  spiral  band  and  bent  striae;  body  very  elongate,  with  a  notch  or 
slit  in  the  outer  lip  of  the  aperture,  or  where  this  is  wanting,  the  striae  are 
bent,  indicating  the  slit.  Murchisonia  are  a  sort  of  elongate  Pleurotomaria. 
Type,  Murchisonia  bilineata. 

Murchisonia  desiderata.    HALL. 

Plate  XXVI.,  figure  8. 

Murchisonia  desiderata,  Hall.     Descpt.  of  New  Sp.  of  Foss. — 1861. 
Murchisonia  desiderata,  Hall.     15th  Rep.  N.  Y.  St.  Cab.— 1862. 
Murchisonia  desiderata,  Hall.    Pal.  N.  Y.,  Vol.  5,  pt.  2,  p.  89—1885. 

Shell  elongate,  turretiform ;  spire  somewhat  rapidly  ascending.  Volutions 
ten  or  more,  and  obtusely  angular,  flattened  on  their  upper  sides,  and  a  little 
more  convex  below  the  spiral  band.  The  volutions,  from  apex  to  aperture,  are 
gradually  enlarging.  The  greatest  width  of  the  last  volution  is  about  equal 
to  the  combined  height  of  the  second  and  third  whorls,  but  scarcely  more  ven- 
tricose  than  the  preceding  one,  except  towards  the  aperture.  Aperture  some- 
what elongate ;  the  columellar  lip  thickened  and  bounded  by  a  well-marked 
callosity. 

Surface  marked  by  distinct,  concentric  striae,  which  are  sometimes  raised 
into  fascicles  above  the  general  surface  of  the  shell,  and,  bending  gently  back 
from  the  suture,  reach  the  spiral  band,  crossing  which,  they  bend  forward  more 
abruptly,  making  a  gentle  curve  to  the  suture  below.  The  spiral  band,  at  about 
three-fifths  of  the  width  of  the  volution  below  the  suture,  is  simple,  flattened 
or  slightly  concave,  limited  by  narrow,  moderately  elevated  revolving  lines, 

GEOL.   SUK. — 22 


170  PALAEONTOLOGY    OF    KENTUCKY. 

and  marked  by  the  retrorsely  curving  striae,  which  are  less  prominent  upon  it 
and  the  adjacent  parts  than  near  the  suture.  Suture  close. 

The  dimensions  and  general  size  of  the  shells  belonging  to  this  species  are 
given  in  the  illustration,  which  shows  the  natural  size  of  the  specimen  from 
which  it  was  made. 

The  specimen  before  me  is  an  internal  cast,  but  it  is  covered  by  a  thin  coral 
bearing  on  its  whole  surface  small  tubercles,  as  shown  in  the  illustration,  but 
not  placed  with  such  a  regularity  as  the  draughtsman  has  given  them  in  the 
figure.  This  incrusting,  tuberculose  coral  was  mistaken  for  the  real  shell  of 
the  fossil. 

Formation  and  Locality.— Found  in  the  cherty  layers  of  the  Devonian  formation  at  and  around 
the  Falls  of  the  Ohio,  in  Kentucky  and  Indiana. 

Mlirchisonia  petilla.      HALL  AND  WHITFIKLD. 

Plate  XXXI.,  figure  5. 

Murchisonia  petilla,  H.  and  "W.     24th  Eegent's  Rep.,  p.  186 — 1872. 
Murchisonia petilla,  H.  and  W.     27th  Regent's  Rep.,  pi.  13 — 1875. 

Shell  small,  spire  elevated,  slender  and  regularly  tapering  from  base  to 
apex ;  volutions  about  twelve  gently  and  regularly  expanding  from  the  apex  ; 
moderately  convex,  somewhat  obtusely  subangular  below  the  middle  ;  last  one 
scarcely  ventricose. 

Aperture  sub-rhomboidal.  Surface  not  known,  the  specimen  being  an  ex- 
foliated internal  cast.  Length  of  the  specimen  one  inch  ;  diameter  of  last  volu- 
tion seven-twentieths,  and  height  one-fifth  of  an  inch. 

Formation  and  Locality. — Occurs  in  the  lower  strata  of  the  Niagara  rocks  in  the  quarries  east  of 
the  city  of  Louisville.  The  specimen  illustrated  and  described  is,  so  far,  the  only  one  known;  it  belonged 
to  the  collection  of  the  late  Dr.  James  Knapp. 


Genus  Pleurotomaria. 


Do  France. 


Pletirotomaria,  De  France.     Diet.  Sci.  Nat.,  41 — 1826. 

Etymology:  pleura,  side;  tome,  cut  or  notch,  having  a  deep  cut  or  notch  in  the  outer  lip. 

Shells  spiral,  trochiform,  solid,  few-whorled,  with  the  surface  variously 
ornamented ;  aperture  subquadrate,  with  a  deep  slit  in  its  outer  margin.  The 
part  of  the  slit  which  has  been  progressively  filled  up  forms  a  band  round  the 
whorls  or  volutions.  This  slit,  in  the  outer  lip  of  the  aperture,  on  which  the 
name  has  been  founded,  is  seldom  visible,  as  specimens  are  rarely  found  per- 
fect ;  but  the  peculiar  bending  of  the  transverse  striae,  curved  backwards  to 
and  marking  the  line  of  the  slit,  are  always  a  prominent  character  of  this 
genus.  (Copied  from  Woodward's  Manual  and  Portlock's  Report  on  London- 
derry.) 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  171 

PleUTOtOmaria  Casii.      MEEK  AND  WORTHEX. 

Plate  XX  VI.,  figure  11. 
Pleurotomaria  cusii,  M.  and  W.     111.  Gcol.,  Vol.  3,  p.  359—1868. 

Shell  attaining  a  rather  large  size,  higher  than  wide;  spire  conical,  a  little 
more  than  equalling  length  of  lower  half  of  body  volution.  Whorls  about 
five  and  a  half,  very  convex;  those  of  the  spire  each  showing  three- fourths  of 
its  entire  height  above  the  next  succeeding  one  ;  upper  ones  (in  casts)  rounded, 
last  one  large  and  ventricose,  and,  like  the  next  above,  sub  angular  around  near 
the  middle,  below  which  it  is  somewhat  produced,  and  rounds  into  a  small, 
umbilical  opening  in  the  cast,  probably  entirely  closed  by  the  columella  in 
specimens  retaining  the  shell.  Spiral  band  apparently  of  moderate  breadth, 
occupying  the  obtuse  angle  a  little  above  the  middle  of  body-whorl,  and  pass- 
ing around  near  the  middle  of  the  others.  Suture  deep  in  consequence  of  the 
great  convexity  of  the  volutions. 

Aperture  sub- circular.  Surface  of  internal  casts  showing,  on  the  upper  con- 
vex slope  of  the  body- whorl,  and  that  of  the  next  above  it,  obscure  transverse 
ridges,  curving  backwards  as  they  extend  out  from  the  suture,  probably  par- 
allel to  the  lines  of  growth.  Crossing  these,  there  is  an  undefined,  revolving 
ridge  on  the  body-whorl  a  little  more  than  half  way  out  from  the  suture 
towards  the  spiral  band.  Other  surf  ace- markings  are  unknown.  (Copied  from 
Meek  and  Worthen's  description  in  Vol.  3,  of  Geol.  Rep.  of  Illinois.) 

This  species  is  easily  distinguished  by  the  transverse  striae,  on  the  upper 
side  of  its  body- whorl,  from  all  other  Silurian  Pleurotomaria. 

Formation  and  Locality. — In  the  Niagara  limestone  of  the  quarries  east  of  the  city  of  Louisville, 
Ky.  A  rather  rare  species. 

Pleurotomaria  arabella.    \.  SP. 

Plate  XXVI.,  figure  12. 

Shell  rather  large,  tilfbinate,  spire  elevated ;  apex  minute,  aperture  sub- 
quadrate,  apparently  somewhat  wider  than  high.  Volutions  five  or  six,  prom- 
inently convex ;  rapidly  enlarging,  last  one  or  body-whorl  very  ventricose. 
Shell  wider  than  high. 

Surface  marked  by  three  revolving  carinae,  of  which  one  is  above  and  the 
other  two  below  the  peripheral  band ;  the  band  itself  is  flat  and  narrow,  and 
not  limited  by  elevated  carinae ;  the  upper  part  of  the  volution,  at  least  in  the 
two  last  ones,  is  gently  sloping  from  suture  to  the  first  or  upper  carina;  from 
this  it  curves  to  the  spiral  band,  forming  a  moderately  deep,  rounded  furrow. 

The  interspaces  between  band  and  second  carina,  and  between  this  and  the 
third  or  last  carination,  are  also  rounded  depressions,  of  which  only  the  one 


172  PALEONTOLOGY    OF    KENTUCKY. 

next  to  the  baud  is  of  about  equal  depth  with  the  furrow  in  the  upper  half ; 
the  second  depression  in  the  lower  half  is  shallow.  In  consequence  of  the 
great  convexity  of  the  volutions  the  suture  is  deep.  The  character  of  the 
transverse  striae  is  only  indicated  but  not  fully  known. 

Formation  and  Locality.— In  Hie  Cornifcrous  limestone  in  Jefferson  county,  Ky.,  and  in  Clark 
county,  Ind.  My  specimen  is  only  an  internal  cast,  from  which  the  surface-markings,  with  the  exception 
of  the  revolving  ctirmae,  are  obliterated.  1  have  compared  this  shell  with  all  the  different  species  of  Pleu- 
rotomaria  known  to  me,  but  can  not  place  it  with  any  one,  and  1  am  thus  compelled  to  make  a  new  species 
for  its  reception. 

Pleurotomaria  lucina.    HALL. 

Kuomphalust  rotundas,  Hall.    Geol.  of  N.  Y.,  Surv.  of  4th  Di&t.— 1843. 
Pleurotomaria  lucina,  Hall.     Descpt.  of  New  Sp.  of  Foss.,  p.  14—1861. 
Pk'iirolomaria  liicirut,  Hall.     Fifteenth  Keg.  Kep.,  pi.  42 — 18G2. 
Pkur.  rotunda  and  P.  lucim,  Hall.     111.  of  Dev.  Foss.  Gastrop,  pi.  8— 187G. 
Pleur.  lucina,  Hall.    Pal.  N.  Y.,  Vol.  5,  part.  2,  p.  G7— 1879. 

Shell  sub-globose  or  obliquely  ovoid-conical.  Spire  moderately  elevated ; 
apex  minute  ;  volutions  about  four,  gradually  expanding  to  the  last  one,  which 
comes  very  regularly  ventricose,  with  the  aperture  expanded  and  nearly  round, 
extended  on  the  lower  side,  with  a  shallow  notch  on  the  anterior  margin ;  upper 
side  of  the  volutions  very  symmetrically  convex ;  suture  neatly  defined, 
slightly  canaliculate ;  lower  side  of  the  body- volution  convex  in  the  middle, 
and  abruptly  curving  into  the  umbilical  depression. 

Surface  beautifully  cancellated  by  concentric  and  revolving  striae,  which,  in 
many  specimens,  are  of  equal  strength.  Periphery  marked  by  a  moderately 
wide  band,  on  which  the  striae  are  turned  abruptly  backwards  ;  this  band  is 
limited  by  stronger  striae  or  narrow  ridges  on  each  side,  sometimes  with  one  or 
two  slender  revolving  striae  within  the  limits  of  the  band,  making  a  narrow 
space,  which  is  often  crenulated  by  the  concentric  striae. 

This  species  is  well  marked  by  its  symmetrically  rotund  form,  with  moderate 
elevation  of  the  spire,  and  the  regular  convexity  of  the  volutions,  even  in  casts 
of  the  interior  when  not  compressed.  There  is  some  variety  in  the  surface- 
markings  of  specimens  apparently  belonging  to  this  species.  The  concentric 
striae  are  sometimes  much  coarser  than  the  revolving  ones  ;  and  finer  striae  are 
implanted  between  the  stronger  ones,  and  do  not  reach  the  suture-line.  In 
old  specimens  the  revolving  band  is  sometimes  nearly  a  quarter  of  an  inch 
wide.  A  very  symmetrical  specimen  has  a  diameter  of  a  little  more  than  two 
inches,  and  is  nearly  an  inch  and  three-fourths  in  height. 

Formation  and  Locality. — Found  in  the  Cornifcrous  limestone,  at  and  around  the  Falls  of  the 
Ohio,  in  Kentucky  and  Indiana,  but  generally  as  internal  casts,  which  show  only  the  general  form,  but  not 
the  surface-markings  of  the  shell. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  173 

Pleurotomaria  procteri.    ».  *r. 

Plate  XXI.,  figures  9,  10  and  13. 

Compare  Pleurotomaria  capillaria,  var.  of  Pal.  N.  Y.,  Vol.  5,  Part  2,  text,  page  87,  and  Pleur.  capillarin, 
var.  rustica,  of  Pal.  N.  Y.,  Vol.  5,  Part  2,  Plates,  Plate  30,  figures  20,  21  and  22. 

Shell  trochii'orm  ;  height  exceeding  width  about  one-fourth  or  more.  Volu- 
tions from  five  to  six,  somewhat  rapidly  increasing  in  size,  the  last  one  ventri- 
cose ;  there  is  only  one  carina  above  and  one  below  the  peripheral  band :  the 
carina  above  the  band  gives  to  upper  portion  of  the  volution  a  sub-angular 
appearance,  while  the  lower  part  is  regularly  rounded.  The  peripheral  band  is 
divided  by  a  somewhat  finer  central  carina,  which  is  crossed  rectangularly  by 
strong  striae,  which  only  extend  from  margin  to  margin  of  the  peripheral  band, 
with  interspaces  of  about  four  times  their  own  size.  These  rectangular  striae 
are  entirely  separated  from  the  striae  of  the  upper  or  lower  half  of  the  volu- 
tion ;  they  give  the  dividing  carina  a  beautifully  crenulated  appearance.  On 
both  sides  of  the  peripheral  band,  the  siirface  is  ornamented  by  strong  trans- 
verse striae ;  in  the  upper  half  they  start  from  the  suture,  and  run  in  an  almost 
straight  line,  with  a  backward  deflection  of  about  ten  degrees,  to  the  first  carina, 
from  where  they  curve  slightly  backward  to  the  upper  marginal  carina  of  the 
peripheral  band.  This  system  of  striae,  interrupted  by  the  band,  continues  at 
the  lower  marginal  carina  of  the  latter,  from  where  the  striae  extend  in  slightly 
curved  or  nearly  straight  lines  with  a  forward  deflection,  either  to  the  sutures 
of  the  upper  volutions,  or  to  the  lower  carina  of  the  body-whorl.  From  this 
lower  carina,  which  forms  the  suture-line  of  the  upper  whorls,  and  which  is, 
therefore,  only  visible  on  the  last  volution,  the  striae  curve  gently  to  the  um- 
bilicus and  to  the  columellar  lip;  but  a  great  number  of  them  die  out  or  become 
extinguished  at  different  distances  from  the  lower  carina.  All  the  volutions 
are,  in  their  transverse  section,  extremely  convex,  which  gives  them  very  deep 
sutures,  and  separates  them  from  each  other  in  a  very  decided  manner.  The 
aperture  of  this  shell  is  not  known,  inasmuch  as  in  all  the  specimens  in  niy 
collection  the  outer  lip  is  missing. 

This  species  stands  between  P.  sulcomarginata  and  P.  capillaria,  both  of 
which  it  resembles  in  some  respect,  but  it  is  easily  distinguished  from  the  first 
by  its  more  elevated  spire,  its  larger  size,  and  the  difference  in  the  number  and 
arrangement  of  the  revolving  carinae ;  from  the  latter  by  the  greatly  smaller 
number  of  revolving  carinae,  and  from  both  here  named,  and  all  other  species 
of  the  genus  Pleurotomaria,  by  the  crenulated  central  carina  in  the  peripheral 
band,  which  is  very  characteristic  in  P.  procteri. 

Formation  and  Locality. — Associated  with  P.  sulcomarginata  in  the  Corniferous  limestone  of  Jef- 
ferson county,  Ky.,  and  of  Clark  county,  I  ml.  It  is  a  somewhat  rare  species.  This  beautiful  shell  I  narno 
in  honor  of  Kentucky's  State  Geologist,  Prof.  John  R.  Procter,  who  has  served  his  State  with  great  dis- 
tinction, and  who  has  labored,  more  than  any  other  man,  to  bring  the  great  mineral  wealth  of  Kentucky  to 
the  knowledge  of  the  people  at  large. 


174  PALEONTOLOGY    OF    KENTUCKY. 

Fleurotomaria  sulcomarginata.    CONRAD. 

Plato  XXI.,  figures  11  and  12. 

Pleur.  sulcomargmata,  Conrad.     Jour.  Acad  Nat.  Sc.  Phil.,  Vol.  8 — 1842. 
Plcur.  sulcomarginata,  Hall.     Descript.  of  New  Sp.  of  Foss.,  p.  18— 18C1. 
Pleur.  sulcomarginata,  Hall.     Fifteenth  Rep.  N.  Y.  St.  Cab. — 18G2. 
Pleur.  sulcomarginata,  Hall.     Illust.  of  Dev.  Foss.  Gastr.,  pi.  19—1870. 
Pleur.  sulcomarginata,  Hall.     Pal.  N.  Y.,  Vol.  5,  part  2,  p.  69—1879. 

Shell  depressed  trochiform  ;  spire  moderately  elevated  ;  apex  minute.  Volu- 
tions four  or  five,  very  depressed  convex  on  the  upper  side,  gradually  enlarging 
to  the  last  one,  which  becomes  somewhat  ventricose.  Aperture  subquadrate, 
somewhat  wider  than  high,  the  columella  much  extended  below. 

Surface  ornamented  by  two  distinct,  narrow,  revolving  carinae  on  each 
volution,  one  just  below  the  suture  and  the  other  near  the  periphery,  with 
finer  intermediate  striae,  which  are  rarely  visible ;  the  entire  surface  marked 
by  strong,  regular  and  even  concentric  striae,  which  crenulate  the  revolving 
carinae,  and,  passing  over  the  lower  one,  bend  backward  to  the  concave  per- 
ipheral band.  Sutures  sometimes  sharply  canaliculate.  In  entire  specimens, 
the  apex  is  very  minute,  and,  when  the  outer  carination  is  crenulated  by  the 
strong  transverse  striae,  the  shell  has  a  coronate  aspect.  This  carination,  how- 
ever, is  often  obsolete  on  the  outer  volution,  and  is  more  rarely  noticed  on  the 
next  above,  and  the  striae  then  continue  uninterruptedly,  bending  backward 
to  the  peripheral  band,  and  continuing  on  the  lower  side,  often  very  nearly  of 
the  same  strength  as  above.  There  is  frequently  a  narrow  depressed  band  just 
below  the  peripheral  band  on  the  last  volution,  causing  a  slight  deflection  of 
the  striae.  The  striae  are  usually  finer,  and  sometimes  become  nearly  obsolete 
below  the  outer  carination,  and  more  rarely  on  other  parts  of  the  shell,  espe- 
cially near  the  aperture. 

Formation  and  Locality. — Found  very  abundantly  in  the  cherty  layers  of  the  Corniferous  lime- 
stone around  the  Falls  of  the  Ohio,  in  Kentucky  and  Indiana,  and  very  often  in  very  fine  and  well  pie* 
Served  specimens. 

Genus  Callonema.    nan. 

Calloncma,  Hall.     Pal.  N.  Y.,  Vol.  5,  pi.  2. 
Etymology:  kallos,  beautiful;  nema,  a  thread. 

Shell  sub-globose,  turbinate  or  ovoid-conical.  Volutions  rounded  or  some- 
times sub-angular  above  and  below  ;  outer  lip  apparently  thin ;  columellar  lip 
thickened  and  spreading  over  the  volutions  above  and  extended  below;  axis 
umbilicate. 

Surface  marked  by  fine,  even  striae,  which  extend  equally  over  the  volutions, 
rarely  divided,  and  sometimes  merging  into  the  ordinary  striae  of  growth,  and 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  175 

extending  into  the  umbilicus.  The  chief  external  characters  of  this  genus 
being  the  sharply  elevated,  even,  thread-like,  concentric  striae  traversing  the 
volutions  above  and  below,  a  distinct  columellar  lip,  and  an  umbilicate  axis. 

Callonema  bellatula.    HALL. 

Plato  XX.,  figures  4,  5,  6  and  7. 

Laxonema  bellatula,  Hall.     14th  Rep.  N.  Y.  St.  Cab.,  p.  104—1861. 
Isonema  bellatula,  Meek.     Proc.  Acad.  Nat.  Sci.  Phil.,  p.  252 — 1865. 
Isonema  bellatula,  Meek.     Geol.  Surv.  of  111.,  Vol.  3,  p.  443—1868. 
Isonema  bellatula,  H.  and  W.     27th  Regent's  Rep.,  pi.  13—1875. 
Isonema  bellatula,  Hall.    Illust.  of  Dev.  Foss.  Gaster.,  pi.  14 — 1876. 
CaOanema  bellatula,  Hall.    Pal.  N.  Y,  Vol.  5,  pt.  2,  p.  51—1879. 

Shell  sub-ovoid-conical ;  spire  elevated  and  rapidly  expanding  below.  Volu- 
tions about  six  or  seven,  the  upper  ones  minute,  and  somewhat  gradually  ex- 
panding to  the  third  or  fourth  whorl,  and  more  rapidly  below,  the  last  one  being 
very  ventricose,  regularly  rounded  or  obtusely  subangular  towards  the  base. 
Aperture  apparently  transverse ;  the  specimen  before  me,  and  represented  by 
figure  7,  is  perfect,  with  the  exception  of  the  peristome,  of  which  the  outer  lip 
is  missing ;  I  am,  therefore,  unable  to  state  the  exact  form  of  the  aperture ;  col- 
umellar lip  thickened,  spreading  above  and  extended  anteriorly.  In  my  speci- 
men the  umbilicus  is  partly  open,  and  partly  closed  by  the  columellar  lip. 

Surface  is  covered  by  regular,  even,  sharply  elevated  striae,  with  about  equal 
interspaces,  which  are  slightly  turned  backwards  from  the  suture,  and  gently 
curved  to  the  base  of  the  volution,  and  on  the  last  one  curving  over  the  per- 
iphery with  equal  strength ;  a  portion  becoming  obsolete  and  others  coalescing 
and  becoming  stronger  as  they  enter  the  umbilical  depression.  Some  specimens 
of  this  species  show  an  obtuse  angularity  at  the  base  of  the  last  volution,  as 
slightly  indicated  in  figure  6 ;  but  most  shells  are  regularly  rounded  and  ven- 
tricose. There  is  no  specific  difference  between  these  two  forms.  This  species 
has  a  close  resemblance  to  Callonema  lichas,  with  which  it  may  even  be  identi- 
cal. 

Formation  and  Locality. — Occurs  in  the  Corniferous  limestone  at  and  around  the  Falls  of  the  Ohio 
in  Kentucky  and  Indiana,  and  belongs  to  the  rarer  forms. 

Callonema  clarki.    N.  sr. 

Plate  XXIV.,  figures  2,  3,  4  and  5. 

Shell  above  medium  size  ;  sub-hemispherical ;  spire  moderately  elevated, 
more  or  less  so  in  different  shells,  as  shown  by  the  two  specimens  illustrated, 
consisting  of  from  three  to  five  volutions.  The  volutions  are  regularly  increas- 
ing from  apex  to  aperture,  which  is  sub-circular  or  subquadrate;  they  are 
depressed  convex  on  their  upper 


176  PALAEONTOLOGY    OF    KENTUCKY. 

The  columella  is  much  extended  below.  Suture  small  and  shallow,  between 
the  upper  volutions  scarcely  noticeable.  The  surface  appears,  to  the  naked 
eye,  entirely  smooth,  but  under  a  magnifier  shows  fine,  transverse  striae,  closely 
set  between  some  stronger  marked  lines  of  growth.  These  striae  and  lines  of 
growth  extend  from  the  suture  down  and  backwards  to  the  umbilical  depres- 
sion. The  last  volution,  or  the  body-whorl,  as  it  is  also  called,  curves  very 
abruptly  at  its  middle,  and  slopes  from  there  in  a  straight  or  slightly  curved 
line  to  the  inner  lip  of  the  aperture,  making  the  lower  half  of  the  last  volution 
either  flat  or  only  very  little  convex.  The  apex  appears  to  be  very  minute  in 
perfect  specimens.  Figure  4  I  consider  to  be  the  normal  form,  while  figure  2  is 
either  an  aberration  or  the  result  of  a  slight  compression. 

Formation  and  Locality. — This  species  occurs  in  the  rotten  hornstone  of  the  Devonian  formation 
and  was  found  by  Dr.  E.  S.  Clark  in  the  Devonian  clay  topping  the  Niagara  rocks  east  of  the  city  of 
Louisville.  I  name  this  heretofore  undescribed  species  in  honor  of  Dr.  Clark. 

Callonema  imitator.      HALL  AND  WHITFIELD. 
Plate  XX.,  figures  12  and  13. 

Pleurotomaria  imitator,  H.  and  W.  24th  Eegent's  Ileport,  p.  195 — 1872. 
Pleurotomaria  imitator,  H.  and  W.  27th  Eegent's  Report,  pi.  13 — 1875. 
Callonema  imitator,  Hall.  Pal.  N.  Y.,  Vol.  5,  par£2,  p.  52—1879. 

Shell  of  large  size,  sub-hemispherical ;  spire  moderately  elevated,  consisting 
of  four  or  five  rounded  volutions,  regularly  increasing  from  the  apex  to  the 
aperture,  which  is  sub-circular ;  rounded  below  and  broadly  umbilicate ;  suture 
distinct,  not  channeled,  situated  at  the  periphery  of  the  preceding  volution. 
Surface  of  the  upper  sides  of  the  volution  marked  by  strong  ridges,  which 
have  a  slight  bend  just  below  the  suture,  and  thence  curve  backward  to  the 
periphery,  gradually  increasing  in  strength  from  apex  to  outer  volution, 
on  the  middle  of  which  they  are  in  the  ratio  of  about  twenty  to  an  inch; 
on  the  outer  half  of  the  last  volution  they  become  gradually  obsolete,  or 
merge  into  the  lines  of  growth,  which  also  mark  every  part  of  the  surface. 

Below  the  periphery  there  are  apparently  none  of  the  ridges  existing.  This 
species  is  very  similar  to  Pleurotomaria  lucina  in  form,  being  a  little  more 
depressed,  and  the  volutions  less  rapidly  increasing.  The  surface-markings 
are  more  nearly  like  those  of  Pleur.  arata,  while  the  volutions  are  more  ventri- 
cose  on  the  upper  side,  and  the  periphery  is  apparently  destitute  of  a  band  or 
sinus,  which  is  a  distinguishing  feature. 

Formation  and  Locality. — In  the  rotten  hornstone  of  the  Corniferous  group,  in  Jefferson  county, 
Ky.,  and  in  Clark  county,  Ind.  Earely  found.  Only  a  few  specimens  are  known  'outside  of  Dr  James 
Knapp's  collection.  A  good  interior  cast  is  in  my  own  cabinet. 


FOSSILS    OF    THE    SILURIAN    AKD    DEVONIAN    ROCKS.  177 

Genus  Loxonema.    phniips. 

Lotonema,  Phillips.     Palaeoz.  Fossils— 1841. 

Etymology :  loxos,  oblique);  nema,  a  thread — alluding  to  the  oblique  thread-like  striae. 

Shell  spiral,  turriculated ;  whorls  or  volutions  convex,  their  upper  edges 
pressed  against  the  next  above ;  without  spiral  band ;  mouth  oblong,  attenu- 
ated above,  effused  below,  with  a  sigmoidal  edge  to  the  right  lip ;  no  umbil- 
icus (?). 

Surface  covered  by  longitudinal  threads,  and  ridges  generally  arched.  (Geol. 
Rep.  of  Londonderry,  by  J.  E.  Portlock.) 

Loxonema  sinuata  is  the  type  of  this  genus. 

Loxonema  hamiltoniae.    HALL. 

Plate  XXXI.,  figure  29. 

Loxonema  hamUtoniae,  Hall.     Dcscpt.  of  New  Sp.  of  Foss. — 1861. 
Loxonema  hnmillonine,  Hall.     15th  Regent's  Rep. — 1862. 
Loxonema  hanrittoniae,  Hall,     lllust.  of  Dev.  Foss.,  pi.  13 — 1876. 
Loxonema  kamiUoiiiae,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  2,  p. '45— 1885. 

Shell  elongate,  subulate ;  volutions  moderately  convex,  numbering  from  ten 
to  thirteen  ;  as  many  as  the  last  number  were  counted  in  the  largest  specimen 
known.  The  volutions  are  gradually  increasing  in  size  from  the  very  minute 
apex  to  the  aperture  ;  the  last  one  becomes  ventricose.  Aperture  ovate,  nar- 
rowing below,  colutnella  extended. 

Surface  marked  by  longitudinal,  sharp,  curving  striae,  which  bend  gently 
backward  from  the  suture,  and  forward  to  the  base  of  the  volution,  having 
the  greatest  curve  near  the  middle,  those  of  the  last  volution  curving  abruptly 
backward  to  the  columellar  lip.  Striae  separated  by  distinctly  defined  grooves, 
which  are  a  little  wider  than  the  ridges,  the  striae  increasing  in  distance  as  the 
shell  grows  older.  In  the  specimen  figured,  the  apical  volutions  are  missing ; 
the  draughtsman  restored  them,  but  he  made  the  volutions  too  high,  and  not 
enough  in  number.  The  height  of  the  figure  would  have  been  the  natural  size 
of  the  shell  when  complete ;  it  should  have  shown  twelve  volutions  instead  of 
its  present  nine.  It  measures  seventeen  lines  in  length,  and  its  body-whorl 
has  a  diameter  of  four  lines.  This  species  is  associated  with  L.  hydraulica, 
which  it  resembles  in  its  surface-markings,  but  it  may  be  easily  distinguished 
from  that  shell  by  the  different  shape  of  the  volutions  and  suture.  In  L.  hy- 
draulica the  whorls  are  very  convex,  while  in  L.  hamiltoniae  they  are  only 
moderately  curved  ;  the  suture  in  L.  hydraulica  is  very  deep  and  constricted, 
that  of  L.  hamiltoniae  comparatively  very  shallow.  Besides,  the  spire  in  L. 

hamiltoniae  is  more  elongate  than  that  of  L.  hydraulica. 

• 

Formation  and  Locality. — Occurs  in  the  chert  bed  which  overlies  the  hydraulic  cement  rock  at  the 
Falls  of  the  Ohio,  on   the  Kentucky  shore  of  the  river,  and  also  at  Watson's  Station,  on  the  Ohio  and 
Mississippi  Railroad,  in  Clark  county,  Ind. 
a  KOI.,  suu. — 22 


178  PALAEONTOLOGY    OF    KENTUCKY. 

Loxonema  hydraulicum.     HALL  AND  WHITFIELD. 

Plate  XX.,   figures  8  and  9. 

Loxonema  hydmulica,  H.  and  W.    24th  Regent's  Rep.,  p.  193—1872. 
Loxonema  hydrautica,  H.  and  W.     27th  Reg.  Rep.,  pi.  13—1875. 
Loxonema  hydraulica,  H.  and  W.     Illust.  of  Dev.  Fossils,  pi.  13 — 1876. 
Loxonema  hydraulicum,  Hall.     Pal.  N.  Y.,  Vol.  5,  part  2,  p.  44 — 1879. 

Shell  turreted ;  volutions  rounded,  from  live  to  eight  and  more ;  greatest 
convexity  about  the  middle  of  each  ;  upper  ones  always  missing,  and,  therefore, 
unknown.  Sutures  deep,  giving  a  constricted  aspect  at  the  junction  of  the 
volutions. 

Surface  marked  with  distinct,  angular  striae,  bending  gently  backward  from 
the  suture  to  the  periphery,  and  with  a  longer  forward  curve  to  the  base  of 
each  volution;  those  of  the  last  volution  bending  more  abruptly  backward, 
and  making  a  second  abrupt  retrorse  curve  to  the  columellar  lip. 

This  species,  in  the  rotundity  of  the  volutions,  and  the  constriction  at  the 
sutures,  contrasts  with  all  the  other  species  of  this  genus  here  described. 

Formation  and  Locality. — Found  rather  plentiful  in  the  cherty  layers  overlying  the  hydraulic 
limestone  of  the  Devonian  formation,  at  and  around  the  Falls  of  the  Ohio,  in  Kentucky  and  Indiana, 
associated  with  Lox.  laeviusculum  and  Lox.  rectistriatum. 

Loxonema  laeviusculum.    HALL. 

Plate  XXII.,  figures  8  and  9. 
Loxonema  laeviitsculum,  Hall.     Pal.  N.  Y.,  Vol.  5,  part  2,  p.  131—1879. 

Shell  elongate,  subulate ;  volutions  from  nine  to  twelve  ;  rounded  and  some 
what  rapidly  expanding  to  the  last  one,  which  is  moderately  ventricose.  Su- 
ture close  and  simple.  Aperture  ovate;  the  columellar  lip  much  extended 
below. 

Surface  nearly  smooth,  or  marked  by  faint,  obsolescent  striae,  which  are 
moderately  curved  over  the  convexity  of  the  volution,  and  become  fasciculate 
on  the  lower  side  of  the  last  one  as  they  approach  the  columellar  lip. 

This  species  has  the  general  aspect  of  Loxonema  hamiltoniae,  but  it  is  less 
rapidly  tapering  towards  the  apex,  the  volution  somewhat  less  convex,  and  the 
last  one  not  so  ventricose  as  in  well  preserved  specimens  of  that  species.  Usu- 
ally the  specimens  have  the  appearance  of  being  worn  and  macerated,  and  the 
general  absence  of  striae  upon  the  surface  may  be  due  in  part  to  this  cause ; 
but  they  are  associated  upon  the  same  surface  with  L.  hydraulicum,  which, 
in  similar  conditions,  has  retained  its  surf  ace- striae  in  good  preservation.  This 
species  is  readily  distinguished  from  L.  hydraulicum  by  the  less  rounded  volu- 
tions and  slighter  constriction  at  the  suture.  It  is  more  rapidly  tapering  than 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  179 

L.  rectistriatum,  with  which  it  is  also  associated,  and  has  no  constriction  of  the 
upper  part  of  the  volution  as  in  that  species. 

A  specimen  preserving  nine  volutions,  including  the  last  one,  measures  about 
one  inch  and  a  quarter. 

Formation  and  Locality. — Occurs  in  the  cherty  layers  above  the  hydraulic  limestone  of  the  Devo- 
nian formation,  at  and  around  the  Falls  of  the  Ohio,  in  Kentucky  and  Indiana.  Not  as  abundant  as  its 
associate,  the  Lox.  hydraulicum. 

Loxonema  rectistriatum.    HALL. 

Loxonema  rectistriatum,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  2,  p.  131 — 1879. 

Shell  elongate  terete  ;  volutions  probably  twelve  and  more  in  number;  mod- 
erately convex,  very  gradually  increasing  in  size ;  the  last  one  being  scarcely 
more  ventricose  than  the  preceding ;  each  volution  is  distinctly  contracted  a 
little  below  the  close  suture,  and  then  expanding,  gives  the  greatest  convexity 
near  the  lower  third.  Suture  line  close ;  aperture  ovate,  with  the  columella 
extending  below. 

Surface  marked  by  slender,  gently  curving,  longitudinal  striae,  which  bend 
backward  from  the  suture  to  bottom  of  constriction,  and  then  continue  to 
the  base  of  the  volution,  those  of  the  last  one  curving  gently  forward  to  the 
columellar  lip.  The  spaces  between  the  striae  are  from  one  and  a  half  to  twice 
the  width  of  the  ridges. 

This  species  may  be  distinguished  from  any  other  described  of  the  genus 
Loxonema,  by  the  finer  longitudinal  striae,  which  are  scarcely  curved  on  the 
body  of  the  volution,  and  also  by  the  constriction  of  each  volution  just  below 
the  suture-line.  The  striae  are  stronger  on  the  upper  volutions,  gradually  be- 
coming finer  and  less  prominent  on  the  lower  ones,  though  continuing  distinct 
throughout.  A  specimen,  which  preserves  about  eight  volutions  from  the 
aperture,  measures  a  little  more  than  one  inch  in  length. 

Formation  and  Locality. — Found  associated  with  Lox.  hydvaulicum  and  Lox.  laeviusculum,  in  the 
cherty  layers  superimposed  upon  the  hydraulic  limestone  of  the  Devonian  formation  at  and  around  the 
Falls  of  the  Ohio,  in  Kentucky  and  Indiana.  Prof.  Hall's  descriptions  and  illustrations  of  this  species,  and 
of  those  just  mentioned  as  its  associates,  were  made  from  specimens  belonging  to  the  cabinet  of  the  late  Dr 
James  Knapp,  who  collected  them  at  the  Falls  of  the  Ohio  on  the  former  Corn  Island. 


Genus  Macrocheilus. 


Phillips. 


Macrocheilus,  Phillips.     Pal.  Fossils — 1841. 
Etymology:  macros,  long;  and  cheilos,  a  lip. 

Synonym:  Polyphemopsis,  Portlock. 

Shell  thick,  ventricose,  buccinoid ;  aperture  simple,  effuse  below ;  outer  lip 
thin,  inner  lip  wanting;  columella  callous,  slightly  tortuous.  Type:  Macro- 
cheilus arculatus  of  Schlotheim.  (Copied  from  Woodward's  Manual.) 


180  PALAEONTOLOGY    OF    KENTUCKY. 

Macrocheilus  carinatus.    N.  SP. 

Plate  XX.,  figures  20,  21,  22  and  23. 

Shell  of  medium  size,  turreted,  sub- fusiform ;  length  less  than  twice  the 
diameter ;  volutions  four  or  five,  gradually  increasing  from  the  apex,  last 
two  ventricose,  and  the  last  one  occupying  one  half  the  length  of  shell. 

Aperture  not  known  ;  indications  point  to  its  being  elongate.  No  surface- 
markings  are  visible  ;  they  may  have  been  obliterated  by  the  process  of  silici- 
fication,  to  which  our  specimens  were  subjected.  A  peculiarity  of  this  shell 
is  the  carina  on  the  periphery  of  the  last  volution,  as  plainly  shown  in  figures 
20  and  23.  It  is  in  fact  not  a  real  carina,  but  produced  by  the  elevation  of  the 
lower  half  of  the  volution  above  the  surface  of  the  upper  half.  This  species 
has  some  resemblance  to  M.  hebe,  but  differs  from  it  by  the  peculiar  feature  of 
its  lower  volution. 

Formation  and  Locality. — Found  in  the  Corniferous  limestone  of  the  Devonian  formation  at  and 
around  the  Falls  of  the  Ohio,  in  Kentucky  and  Indiana. 

Genus  Polyphemopsis,    Poniock. 

Polyp hemop sis,  Portlock.     Geol.  Hep.  of  Londonderry — 1843. 

Etymology:  polyphemus,  a  genus  of  shells;  opsis,  appearance — having  the  appearance  of  Poly- 
phemus. 

Portlock  does  not  give  a  definite  description  of  the  genus  ;  but  from  his 
article  on  the  subject,  the  following  description  may  be  formulated : 

Shell  free,  univalve  elongated,  with  a  mammillated  spire ;  mouth  narrow  ; 
columella  smooth  and  truncated ;  base  notched ;  the  last  whorl  greater  than 
the  balance  together ;  base  of  the  columella  curved ;  outer  lip  is  not  margin- 
ated,  and  does  not  form  on  the  whorls  any  suture  or  varices  which  might  indi- 
cate the  position  of  former  apertures. 

This  is  the  description  of  Montfort's  genus,  Polyphemus,  from  which  Port- 
lock's  Polyphemopsis  differs  by  its  sharp  spire,  while  Polyphemus  has  a  mam- 
millated one,  and  by  the  want  of  a  wave  in  outer  lip  of  the  aperture. 

Polyphemopsis  louisvillae.      HALL  AND  WHITFIELU. 

^Plate  XX.,  figures  16,  17,  18  and  19. 
Polyphemopsis  louismllae,  H.  and  W.     24th  Reg.  Eep.,  p.  193 — 1872. 

Shell  small,  ventricose,  consisting  of  about  six  rapidly  tapering  volutions, 
the  last  of  which  comprises  about  two-thirds  the  entire  length  of  shell.  Aper- 
ture large,  ovate,  widest  below  the  middle,  and  pointed  at  the  upper  angle ;  a 
little  more  than  half  as  long  as  the  shell.  Columella  slight ;  suture  scarcely 
impressed. 


FOSSILS    OF    THE    SILURIAN    ANL>    DEVONIAN    ROCKS.  181 

Surface  smooth ;  figures  16  and  17  are  of  natural  size,  while  figures  18  and  19 
are  enlarged  to  two  diameters.  Figures  and  description  made  from  specimens 
belonging  to  the  collection  of  the  late  Dr.  James  Knapp. 

Formation  and  Locality. — Occurs  in  the  hydraulic  limestone  of  the  Devonian  formation  at  the 
Falls  of  the  Ohio,  in  Kentucky  and  Indiana. 


Genus  Euomphalus. 

Euomphalus,  Sowerby.     Minn.  Conch.,  Vol.  1 — 1814. 
Etymology:  eu,  wide;  omphalos,  umbilicus, 

The  type  of  this  genus  is  Euomphalus  pentagonalis.  Shell  depressed  or 
discoidal ;  whorls  angular  or  coronated ;  aperture  polygonal ;  umbilicus  very 
large ;  operculum  shelly,  round,  multispiral.  The  genus  Euomphalus  is  nearly 
related  to  Straparollus  of  Montfort,  and  to  Phanerotinus  of  Sowerby.  It  is  dif- 
ficult to  mark  out  any  features  of  importance  in  which  these  three  genera  differ. 
Prof.  Hall  uses  the  name  Straparollus  in  a  sub-generic  sense  for  those  shells 
with  close  rounded  volutions,  where  the  spire  rises  moderately  above  the  plane 
of  the  outer  volution,  while  those  shells  with  disjointed  volutions  form  the 
genus  Phanerotinus. 

Euomphalus  decewi.    BILLINGS. 

Plate  XXI.   figures  1  and  2. 

Euomphalus  decewi,  Billings.     Can.  Jour.,  p.  358 — 1861. 
Euomphalus  conradi,  Hall.     14th  Reg.  Rep.,  p.  107 — 1861. 
Euomphalus  decewi,  Meek.     Geol.  Rep.  Ohio  Pal.,  Vol.  1 — 1873. 
Euomphdlus  decewi,  Hall.     Illust.  of  Dev.  Poss.,  pi.  15 — 1876. 
Euomphalus  decewi,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  2,  p.  65—1879. 

Shell  discoid,  upper  side  moderately  concave  or  sometimes  nearly  flat,  the 
lower  side  broadly  and  deeply  concave.  Periphery  moderately  convex  or 
nearly  flat,  and  slightly  oblique  to  the  plane  of  the  shell ;  sometimes,  in  the 
casts  of  young  shells,  gently  rounded  from  the  upper  margin  to  the  edge 
of  the  umbilical  depression.  Volutions  three  or  four  (there  are  rarely  more 
than  two  or  three  preserved  in  the  casts),  inner  ones  rounded,  gradually  be- 
coming depressed  on  the  upper  and  lower  sides.  The  periphery,  at  first 
rounded  and  undefined,  becomes  more  flattened  and  distinctly  limited  by  a 
defined  angularity  above  and  below,  becoming  more  flattened  towards  the 
aperture ;  the  upper  side  being  gently  depressed,  while  the  lower  side  grad- 
ually assumes  a  more  abruptly  concave  aspect,  forming  a  broad  umbilicus. 
Aperture  unknown;  section  of  the  outer  volution  sub-quadrilateral  or  tri- 
angular, with  the  inner  angle  truncated. 


182  PALEONTOLOGY    OF    KENTUCKY. 

Surface,  in  young  specimens,  marked  by  fine  elevated  striae  of  growth.  The 
fossils  has  a  diameter  of  from  one  to  four  inches. 

This  species  occurs  usually  as  internal  casts ;  in  those  of  older  specimens 
the  apex  is  decollated,  and  the  termination  smoothly  rounded,  as  if  separated 
by  a  septum,  no  evidence  of  a  continuation  above  being  perceptible.  The 
interior  volutions  being  rounded,  the  angularity  on  the  upper  side  is  scarcely 
noticeable  before  the  end  of  the  second  volution,  and  that  of  the  lower  side 
about  the  same  time  or  a  little  later.  In  some  of  the  casts  of  the  interior  there 
is  a  low,  undefined  angularity  upon  the  back  of  the  shell.  This  species  ap- 
pears to  be  nearly  identical  with  Euomphalus  wahlenbergii  of  Goldfuss  (Petre- 
facta,  vol.  3,  p.  82,  pi.  189,  figs.  7,  a,  &),  found  in  the  limestone  of  the  Eifel. 
That  species  also  presents  the  same  features  in  the  decollation  of  the  earlier 
volutions,  and  the  rounded  apical  extremity.  That  European  form  is  associated 
with  Euomph.  planorbis,  a  species  much  resembling  our  Euomph.  clymen- 
ioides,  which  occurs  in  the  same  beds  with  Euomph.  decewi,  in  western  local:- 
ties. 

Formation  and  Locality. — Found  abundantly  in  the  Corniferous  limestone  in  Jefferson  county, 
Ky.,  and  Clark  county,  Ind.  A  specimen  containing  the  shell  is  figured  in  Geol.  Ohio  Pal.,  Vol.  1. 

Euomphalus  sampsoni.    N.  SP. 

Plate  XXI.,  figures  3  and  4. 

Shell  discoid,  but  generally,  by  apical  decollation,  receiving  the  shape  of  a 
horn;  both  sides  considerably  concave  ;  the  periphery  broadly  convex.  Num- 
ber of  volutions  unknown,  probably  only  two.  The  outer  volution  rapidly 
increasing  in  size;  its  cross-section  near  the  apex  circular,  near  the  aperture 
oval.  The  surface  is  ornamented  by  from  twenty-five  to  thirty  strong,  simple 
plications,  each  of  which  extends  over  the  whole  length  of  the  outer  or  last 
volution,  and  may  probably  reach  back  to  the  apex.  These  plications  increase 
in  strength  from  apex  to  the  aperture;  their  interspaces  are  also  gradually 
widening  in  their  course  towards  the  front ;  they  are  of  unequal  width  ;  some 
are  of  four  times,  and  others  of  double  the  size  of  the  adjacent  ribs.  My 
specimens,  being  internal  casts  completely  silicified  into  hornstone,  no  other 
surface-markings  are  retained. 

Form  and  size  of  the  aperture  unknown.  This  species,  with  decollated  apex, 
showing  only  a  horn  of  not  quite  a  whole  volution,  resembles  somewhat  Prof. 
Hall's  Nautilus  liratus,  with  which  I  confounded  it,  when  I  found  the  first 
specimen,  but  I  soon  discovered  my  mistake.  Hall's  Nautilus  shows  plainly 
the  transverse  lines  of  the  septae,  which  do  not  exist  in  our  shell ;  in  the  latter 
the  curvature  is  greatly  stronger  than  in  the  former,  and  the  increase  in  the 
size  of  the  outer  volution  is  more  gradual  in  my  species  than  in  the  Nautilus. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  183 

The  specimen  illustrated  on  plate  21  is  about  of  average  size,  and  represents 
the  general  condition  of  most  of  the  specimens  so  far  found. 

Formation  and  Locality. — Found  in  the  cherty  layers  superimposed  upon  the  hydraulic  limestone 
of  the  Devonian  formation,  at  Watson's  Station,  in  Clark  county,  Ind.,  about  six  miles  from  the  Falls  ot 
the  Ohio.  This  species  is  named  to  honor  a  gentleman  who  cultivates,  not  only  for  himself,  different 
branches  of  Natural  Science,  among  which  most  prominently,  Geology  and  Palajontology,  but  who  also 
endeavors  to  popularize  the  same  by  forming  scientific  societies  in  his  western  home.  It  is  named  after  the 
Hon.  F.  A.  Sampson,  attorney  at  law,  Sodalia,  Missouri 

Genus  Platyostoma.    conrud. 

Platyostoma,  Conrad.    Jour.  Acad.  Nat.  Sci.  Phil.,  Vol.  8—1842. 
Etymology  :  platys,  broad  ;  stoma,  mouth. 

Mr.  Conrad  gives  the  following  very  meager  description  of  this  genus : 
Shell  sub-globose ;  spire  short ;  aperture  very  large,  sub-orbicular,  dilated ; 
labrum  joining  the  body-whorl  at  right-angles  to  the  axis  of  shell.  The 
species,  Platyostoma  niagarensis  or  P.  lineata,  may  be  taken  as  the  type  for 
this  genus.  The  shells  of  this  genus  are  related  to  those  of  Platyceras,  with 
depressed  spire,  but  they  differ  by  the  larger  number  of  their  volutions  and  the 
more  gradual  increase  in  the  size  of  the  whorls. 

Flatyostoma  lineata.    CONRAD. 

Plate  XXI.,  figures  7  and  8,  and  Plato  XIX.,  figures  6,  6,  7  and  8. 
,  Platyostoma  lineata,  Conrad.     Jour.  Acad.  Nat.  Sci.  Phil.,  Vol.  8—1842. 
Platyostoma  lineata,  Hall.     Illust.  of  Devonian  Foss.,  Gast..  pi.  9 — 1876. 
Platyostoma  lineata,  Hall.    Pal.  N.  Y.,  Vol.  5,  part  2,  p.  21—1876. 

Shell  above  medium  size,  depressed  spiral ;  each  volution  elevated  moder- 
ately above  the  succeeding  one ;  number  of  volutions  seldom  exceeding  four ; 
apex  being  usually  imperfect.  The  outer  volution  large  and  very  ventricose  ; 
it  is  regularly  convex,  with  the  exception  of  the  portion  near  the  suture  line, 
which  is  generally  a  little  depressed  or  concave.  Aperture  sub-rhomboidal, 
with  thin  outer  lip  and  a  sharp  entire  margin ;  columellar  lip  thickened,  folded 
and  renexed  over  the  umbilicus,  which  is  entirely  closed  in  adult  speci- 
mens. 

Surface  marked  by  fine,  nearly  equidistant,  thread-like  revolving  striae,  as 
seen  in  figures  5  to  8,  plate  19.  which  are  cancellated  by  fine  concentric  striae 
of  about  the  same  strength,  but  of  unequal  distance ;  the  latter  sometimes 
bend  abruptly  backward  upon  the  back  of  the  shell,  indicating  a  sinus  in  the 
lip  at  some  period  of  growth,  and  are  frequently  crowded  in  fascicles,  giving 
a  rugose  appearance  to  the  surface  of  the  shell.  In  well  preserved  specimens 
the  surface  is  beautifully  cancellated;  and  in  worn  and  partially  exfoliated 


184  PALAEONTOLOGY    OF    KENTUCKY. 

specimens,  some  of  the  surface-markings  remain  visible ;  the  revolving  striae 
are  generally  the  first  which  become  obliterated.  This  species  is  very  variable 
in  size ;  we  find  specimens  as  small  as  half  an  inch  or  less,  and,  again,  others 
measuring  even  more  than  two  inches.  The  individuals  illustrated  on  plates 
19  and  21  are  about  of  average  size. 

Formation  and  Locality. — Found  abundantly,  in  even  well  preserved  specimens,  however,  without 
the  revolving  striae,  in  the  rotten  limestone  of  the  Corniferous  group,  in  Jefferson  county.,  Ky.,  and  in 
Chirk  county,  lnd. 

Flatyostoma  lineata,  var.  callosa.    HALL. 

Plate  XXI.,  figure  14;  Plate  XXII.,  figures  10  and  11,  and  Plate  XXV.,  figures  5,  0  and  7. 

Plaiyostoma  lineata,  var.  callosa,  Hall.     Illust.  of  Dev.  Fossils,  Gasteropoda,  pi.  9 — 1876. 
Platyostoma  lineata,  var.  callosa,  Hall.     Pal.  N.  Y.,  Vol.  5 — 1879. 

This  variety  has  the  general  form  and  also  the  surface-markings  of  specimens 
of  the  species  Plat,  lineata,  with  the  exception  that  in  this  variety  the  spire 
is  extremely  depressed,  scarcely  extending  above  the  upper  level  of  the  volu- 
tion of  habitation,  which  is  generally  called  the  body-whorl.  The  aperture  is 
large,  sub  orbicular,  with  the  peristome  slightly  sinuate  on  the  upper  side  near 
its  junction  with  the  preceding  volution.  The  inner  lip  is  marked  by  a  thick- 
ened callus,  not  observed  in  any  other  specimens  ;  the  callosity  extending  into 
the  lip  below,  which  thence  assumes  the  ordinary  features  of  the  species. 

Formation  and  Locality. — Found  associated  with  Plat,  lineata  in  the  rotten  hornstone  of  the 
Devonian  formation,  in  Jefferson  county,  Ky.,  and  in  Clark  county,  lnd. 

Platyostoma  turbinata.    HALL. 

Plate  XXI.,  figures  5  and  6. 

Platyostoma  turbinata,  Hall.     Fourteenth  Rep.  N.  Y.  St.  Cab.— 1861. 
Plaiyostoma  turbinata,  Hall.     Illust  of  Dev.  Foss.,  pi.  10—1876. 
Plattjosloma  turbinata,  Hall.    Pal.  N.  Y.,  Vol.  5,  part  2,  p.  27—1879. 

Shell  sub-turbinate,  sometimes  approaching  a  sub-globose  form.  Spire  de- 
pressed, or  more  or  less  elevated  above  the  outer  volution,  sometimes  nearly 
on  the  same  plane ;  volutions  three  or  four  rapidly  expanding,  the  last  ex- 
tremely ventricose,  with  the  lower  part  projected  in  the  direction  of  the  col- 
umella,  which  is  much  extended.  Aperture  sub-ovate,  broader  above,  narrow- 
ing, and  often  extended  below. 

Surface  marked  by  fine,  sub-equal  concentric  striae,  crossed  by  finer  revolv- 
ing striae;  the  former  variously  undulated  upon  the  surface,  indicating 
sinuosity  in  the  lip  of  the  aperture  at  former  stages  of  growth.  In  older 
shells  the  striae  become  lamellose  and  often  crowded  in  fascicles. 

Formation  and  Locality.— In  the  Corniferpus  group  around  the  Falls  of  UIQ  Qhio,  in  Kentucky 
and  Indiana. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  185 

Platyostoma  turbinata,  var.  cochleata.    HALL. 

Platyostoma  hirbinata,  var.  cochhata,  Hall.     Illust.  of  Devonian  Fossils,  Caster.,  pi.  10 — 187G. 
Platyostoma  turbinata,  var.  cochleata,  Hall.     Pal.  N.  Y ,  Vol.  6,  part  2,  p.  28—1879. 

Shell  turbinate.  Spire  elevated,  conical ;  volutions  about  four  or  five ;  per- 
iphery of  the  last  volution  obtusely  rounded  or  distinctly  sub-angular,  with 
a  sinus  in  the  margin  of  the  aperture  ;  the  last  volution  sometimes  becoming 
free  near  the  aperture,  which  latter  is  obliquely  sub-ovate  or  ovate  ;  peristome 
sinuous,  often  with  a  deep  notch  in  the  upper  margin,  and  sometimes  con- 
tinued in  a  columellar  extension  below. 

The  specimens  referred  to  this  variety  all  agree  in  having  an  elevated  spire, 
with  rounded  volutions  above  the  last  one,  which  is  almost  invariably  sub- 
angular. 

Formation  and  Locality. — Found  associated  with  Plat,  lineala  in  the  rotten  hornstone  of  the  Devo- 
nian formation  around  Louisville,  Ky. 

Platyostoma  niagarense.    HALL. 

Plate  XXXIII.,  figure  30. 

Platyostoma  niagarenm,  Hall.     Pal.  N.  Y.,  Vol.  2,  p.  287,  pi.  60,  figs,  la-lv— 1852. 
Platyostoma  niagarense,  Hall.    28th  Rep.  N.  Y.  St.  Mus.  Nat.  Hist.,  Mus.  edit.,  p.  175,  pi.  28,  figs.  1-12;  pi. 

29,  figs.  1-15—1879. 
Platyostoma  niagarnwe,  Hall.     Ind.  Geo.  Survey,  llth  Rep.,  pi.  29,  p.  318—1881. 

The  following  description  is  quoted  from  Prof.  Hall :  Shell  ovoid  or  sub- 
globose  ;  volutions  three  to  four,  the  last  one  very  ventricose ;  spire  varying 
from  the  plane  of  the  outer  volution  to  an  elevation  of  one-fifth  or  one-fourth 
the  height  of  the  shell  above. 

Apex  minute,  somewhat  rapidly  expanding,  the  first  two  volutions  usually 
symmetrical ;  the  outer  volution  often  unsymmetrical,  very  ventricose  and 
regularly  rounded  upon  the  back,  but  not  unfrequently  extended  and  becoming 
free  towards  the  aperture,  and  marked  on  the  upper  or  lower  side,  or  upon 
both,  by  a  groove,  along  which  .the  striae  are  abruptly  bent,  indicating  a  sinus 
in  the  peristome  during  some  period  of  its  growth ;  peristome  entire  or  undu- 
lated, sometimes  distinctly  notched  in  the  margin,  free  or  adhering  on  the 
columellar  side,  and  sometimes  expanded  and  presenting  a  thickened  callosity 
or  oolumellar  lip. 

Surface  marked  by  fine  undulating  striae  of  growth,  which  sometimes  become 
lamellose.  In  well  preserved  specimens,  finer  revolving  striae  cancellate  the 
striae  of  growth,  and  sometimes  the  surface  is  marked  by  revolving  ridges. 

Formation   and   Locality. — Occurs   in   the   Niagara   near  Louisville,    Kentucky.      The  specimen 
figured  is  a,  very  young  one. 
OEOL.  SUK. — 24 


186  PALEONTOLOGY    OF    KENTUCKY. 

Genus  Strophostylus. 


Strophostylus,  Hall.    Pal.  N.  Y.,  Vol.  3,  page  303—1859. 
Etymology  :  strophe,  turning  around  ;  stylos,  a  column. 

Shell  sub-globose  or  ovoid-globose  ;  spire  small,  with  a  large  ventricose 
body-whorl.  Outer  lip  thin,  not  reflected,  sometimes  slightly  expanded. 

Columella  twisted  or  spirally  grooved  within  ;  not  reflected.  No  umbilicus. 
Aperture  somewhat  round-ovate  or  transversely  broad  oval. 

Strophostylus  varians.    .HALL. 

Plate  XXII.,  figures  6  and  7. 

Strophostylus  varians,  Hall.     111.  of  Dev.  Foss.,  pi.  2  —  1876. 
Strophostylus  varians,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  2,  p.  31—1879. 

Shell  of  medium  size,  spiral,  with  moderately  elevated  spire;  volutions 
about  three  or  four;  ventricose  and  regularly  rounded  above,  and  somewhat 
rapidly  increasing,  the  last  one  becoming  very  ventricose,  and  extending 
downward  and  forward.  Aperture  ovate  or  sub  orbicular  ;  peristome  entire  ; 
the  columellar  lip  usually  expanded,  and  spreading  over  the  umbilicus,  some- 
times free,  and  leaving  the  umbilicus  exposed. 

Surface  covered  by  fine,  closely  set,  transverse  striae,  the  suture,  owing  to 
the  great  convexity  of  the  volutions,  deep  and  well  exposed.  Prof.  Hall 
makes  the  following  remarks  about  this  species:  u  This  species,  in  some  re- 
spects, makes  a  wider  departure  from  the  typical  forms  of  Strophostylus  than 
any  other  of  the  genus  known  to  me.  The  peculiar  and  characteristic  form  is 
preserved  ;  the  symmetrical  rounding  of  the  volutions  above,  and  the  delicately 
formed  spire,  as  well  as  the  form  of  the  aperture  in  some  specimens,  are  all 
characteristic  of  the  genus.  The  striae,  however,  have  a  tendency  to  become 
lamellose  or  interruptedly  undulating  ;  and  there  are  evidences  of  irregularity 
of  growth  and  indentations  in  the  margin  of  the  peristome,  both  above  and 
below  the  periphery.  The  form  of  the  aperture  is  extremely  variable,  from 
narrow  elliptical  to  broadly  expanded.  There  is,  though  rarely,  a  tendency  in 
the  last  volution  to  become  free,  and  the  characteristic  plication  of  the  colum- 
ellar lip  is  not  often  well  preserved.  In  some  of  its  variations  it  simulates 
Platyostoma,  but  in  all  phases  it  differs  from  that  genus  in  the  characteristic 
expression  of  the  spire." 

Formation  and  Locality.—  Occurs  in  the  Corniferous  limestone  at  and  around  the  Palls  of  the  Ohio 
in  Kentucky  and  Indiana;  but  it  is  a  rather  rare  shell  in  our  rocks. 


FOSSILS    Otf    THE    SILURIAN    AND    DEVONIAN    ROCKS.  187 


Genus  Cyclonema,    Han. 

Cyclonema,  Hall.     Pal.  K  Y.,  Vol.  2—1852. 
Etymology:  kuklos,  a  circle;  nema,  a  thread. 

Shells  turbinate,  thin;  spire  short,  consisting  of  few  volutions,  which  in- 
crease rapidly  from  the  apex ;  aperture  large,  rounded  anteriorly,  and  some- 
what flattened  on  the  columella  side ;  umbilicus  none ;  surface  strongly 
marked  by  spiral,  thread-like  striae,  which  are  cancellated  by  finer  striae. 

This  genus  includes  shells  which  have  been  referred  to  Pleurotomaria,  Litto- 
rina  and  others,  but  which  have  no  slit  or  indentation  in  the  outer  lip  or  a 
band  upon  the  volutions. 

The  surface  is  marked  by  elevated  striae  parallel  to  the  direction  of  the 
volutions,  and  the  spaces  between  these  are  marked  by  finer  striae  crossing  the 
others  obliquely  ;  tliese  latter,  however,  are  often  obsolete. 

The  Pleurotomaria  bilix  of  Conrad  is  the  type  of  this  genus. 

Cyclonema  cancellata.    HALL. 

Plate  XX.,  figures  10  and  11. 

Littorina  cancellata,  Hall.     Geol.  Kep.  4th  Dist.  N.  Y. — 1843. 
Cyclonema  cancellata,  Hall.     Pal.  N.  Y.,  Vol.  2,  page  90 — 1852. 

Obtusely  sub-conical  or  globose,  with  a  short  spire ;  volutions  about  four, 
rounded,  rapidly  increasing  from  the  apex,  so  that  the  last  one  occupies 
almost  the  whole  bulk  of  the  shell ;  aperture  scarcely  expanded. 

Surface  marked  by  prominent  thread-like  lines,  coincident  with  the  spire, 
which  are  decussated  by  finer  elevated  striae  in  a  slightly  oblique  direction. 

The  size  of  this  shell  varies  greatly,  from  one  measuring  only  a  few  lines  to 
the  size  shown  in  the  illustrations.  In  .young  individuals,  the  decussating 
striae  are  usually  well  preserved,  while  they  gradually  become  obsolete  in  older 
specimens,  which  are  also  often  distorted  by  pressure. 

Formation  and  Locality.— Occurs  in  the  lower  strata  of  the  Niagara  group  in  the  quarries  east  of 
the  city  of  Louisville,  where,  however,  it  is  a  very  rare  shell.  The  specimen  from  which  this  description, 
and  the  figures  10  and  11,  on  plate  20,  were  made,  belonged  to  the  collection  of  the  late  Dr.  James  Knapp; 
no  others  are  known  to  me. 

Gyclonema  rugaelineata.    HALL  AND  WHITFIBLD. 

Plate  XXXIII.,  figure  21. 

Euomphalus  (Cyclonema)  rugaelineata,  H.  and  W.    24th  Rep.  on  N.  Y.  State  Cabinet,  p.  186—1872. 
Euomphulus  (Cyclonema)  rugaelineata,  H.  and  W.    27th  Rep.  on  N.  Y.  State  Cabinet,  pi.  13 — 1875. 

Shell  of  medium  size,  depressed  turbinate,  with  four  or  five  volutions,  which 
increase  very  rapidly ;  they  are  rounded,  very  convex,  and  the  last  one  is  very 


188  PALEONTOLOGY    OF    KENTUCKY. 

ventricose.  The  surface  is  ornamented  by  ten  to  twelve  strong,  sharply  ele- 
vated, revolving  lines,  having  a  smaller  one  between  them.  On  the  upper  half 
of  the  body-whorl  the  stronger  revolving  lines  have  larger  interspaces  than 
those  on  the  lower  half,  but  the  lines  in  the  interspaces  are  smaller  above  the 
center  of  the  volution  than  those  below  it.  Between  suture  and  the  upper 
carina  or  strong  revolving  line,  there  are  four  very  fine  revolving  lines,  only 
indicated  by  the  four  rows  of  imbrications,  which  are  there  conspicuously 
marked.  These  revolving  striae  are  crossed  transversely  by  irregular  lamellose 
lines  of  growth,  to  which  the  surface  owes  its  finely  .ornamented,  somewhat 
rugose  appearance. 

Suture,  owing  to  the  great  convexity  of  the  volutions  in  their  cross-sections, 
deep  and  sharply  marked. 

Apex  and  the  first  one  or  two  volutions  not  known  on  account  of  the  decol- 
lated condition  of  the  shell.  Aperture  supposed  to  be  round ;  form  of  base 
and  columella  unknown. 

Prof.  Hall  states  that  this  species  bears  considerable  resemblance  to  Euom- 
phalus  carinatus  of  Sowerby,  found  in  Europe  in  the  Niagara  group,  from 
which  it  differs  by  the  smaller  number  of  revolving  carinae,  and  in  the  posses- 
sion of  the  intermediate  lines,  as  also  in  the  character  of  the  transverse 
striae. 

Formation  and  Locality. — In  the  Niagara  strata  of  the  different  quarries  east  of  the  city  of  Louis- 
ville, Ky.  My  illustration  of  this  shell  is  a  copy  of  Prof.  Hall's,  who  made  his  from  a  not  very  good  speci- 
men in  Dr.  James  Knapp's  collection.  That  specimen  was,  for  some  time,  the  only  one  known  ;  but  since 
then  I  have  found  several  myself.  One  of  my  shells  is  not  at  all  distorted,  showing  three  volutions  in  their 
regular  form,  and  with  their  surface  ornamentation,  except  the  markings  on  the  lower  half  of  the  last 
volution. 

Cyclonema  multilira.    HALL. 

Plate  XXII.,  figure  5. 

Cychnema  multilira,  Hall.  Descr.  NewiSp.  of  Fossils,  p.  20 — 1861. 

Ct/donema  multilira,  Hall.  Fiteenth  Rep.  N.  Y.  State  Cab.  Nat.  Hist.,  p.  48—1862. 

Ci/cJojiema  multilira,  Hall.  Illustrations  of  Devonian  Fossils,  Gasteropoda,  pi.  12—1876. 

Cyclonemu  mullWra,  Hall.  Pal.  N.  Y.,  Vol.  5,  pt.  2,  pi.  12—1879. 

Shell  medium  size,  pyramidal  in  outline,  gently  turbinate,  with  four  increas- 
ing volutions;  suture  line  indistinct.  On  the  surface  of  the  volutions  are 
regular,  prominent  plications,  and  very  broad  sinuous  furrows,  winding  par- 
allel to  the  suture- line.  Volutions  begin  sharply,  but  increase  in  diameter, 
and  become  a  little  more  ventricose. 

The  description  is  based  upon  a  very  imperfect  cast,  in  which  the  lip  and 
umbilicus  are  wanting. 

Formation  and  Locality.— From  the  lower  Devonian  near  Louisville,  Ky. 


FOSSILS    OF    THE    SILURIAN    ANI>    DEVONIAN    ROCKS.  189 

Genus  Trochonema.    saitor. 

Etymology :  trochos,  a  wheel ;   nema,  a  thread. 

This  genus  is  never  defined  by  any  writer  in  this  country.  It  includes  spiral 
shells,  having  some  relations  to  Pleurotpmaria,  but  differing  from  that  genus 
by  exterior  characters. 

Trochonema  fatua.    HALL. 

Trochonema  fatua,  Hall.     20th  Reg.  Rep.,  page  345—1867. 

Spire  elevated ;  shell  turritiform,  consisting  of  about  four  or  five  volutions, 
which  gradually  increase  to  the  last  one,  which  is  moderately  ventricose  ;  volu- 
tions biangular,  leaving  a  flattened  space  upon  the  back  about  equal  to  flattened 
space  between  upper  angle  and  suture  line ;  lower  half  of  last  volution 
rounded ;  aperture  ovate-elongate.  The  specimens  from  which  this  descrip- 
tion was  made  by  Prof.  Hall  were  casts,  and  so  is  the  one  before  me,  which 
answers  in  every  particular  the  above  description.  Prof.  Hall  states  that  the 
surface  of  the  shell,  as  seen  in  an  imprint  in  the  rock,  is  finely  striated,  and 
that  the  flattened  space  on  the  back  of  volution  is  margined  on  each  side  by  a 
slender  carina,  and  is  covered  by  coarser  striae. 

The  size  of  different  specimens  varies  greatly ;  its  height  is  from  one  to  one 
and  seven-eighths  of  an  inch,  while  the  diameter  of  its  base  is  about  four- 
fifths  of  its  height. 

Formation  and  Locality. — Found  in  the  Niagara  rocks,  in  the  quarries  east  of  the  city  of  Louis- 
ville, Ky.  It  is  very  rare;  the  only  specimen  known  to  me  belongs  to  the  collection  of  Major  "Win.  J. 
Davis,  of  Louisville,  Ky. 

Trochonema  rectilatera.    HALL. 

Plate  XX.,  figures  1  and  2. 

Trochonema  redilatera,  Hall.    24th  Regent's  Rep.,  p.  193—1872. 
Trochonema  rectilatera,  Hall.    27th  Regent's  Rep.,  pi.  13—1875. 

Shell  of  medium  size,  turbinate  ;  breadth  and  height  almost  equal ;  volution 
about  five,  carinated  above  with  straight,  nearly  vertical  sides ;  outer  one  ven- 
tricose, with  two  carinae  having  a  wide,  vertical,  slightly  concave  space  be- 
tween, which  occupies  more  than  one-third  the  height  of  the  volution.  Upper 
side  of  the  volutions  convex  for  half  the  distance  to  the  carina,  and  below  this 
they  are  concave,  giving  the  form  of  an  ogee. 

In  another  specimen,  apparently  the  upper  [side  of  the  volutions  are  slightly 
concave,  and  regularly  sloping  downward  from  the  suture  to  the  carina.  Lower 
side  of  the  volution  not  carinate  ;  umbilicus  small,  or  closed  with  a  callosity 


190  PALEONTOLOGY    OF    KENTUCKY. 

Surface  marked  by  fine  striae  of  growth,  which  are  turned  backward  from 
the  suture,  and  are  vertical  on  the  sides  of  the  volution,  and  on  the  lower  side 
curve  backward  to  the  umbilical  area. 

Formation  and  Locality. — In  the  upper  strata  of  the  Devonian  limestone,  at  and  around  the  Falls 
of  the  Ohio,  where  it  is  exceedingly  rare.  As  Dr.  Knapp's  collection,  which  contained  the  original  speci- 
mens, is  sold,  I  don't  think  there  exists  a  representative  of  this  species  in  the  Falls  Cities. 

Trochonema   yandellana.      HALLAND  WHITFIELD. 

Plate  XX.,  figure  3. 

Trochonema  yanaellana,  H.  and  W.     24th  Regent's  Rep.,  p.  194 — 1872. 
Trochonema  yandellana,  H.  and  W.    27th  Regent's  Rep.,  pi.  13 — 1875. 

Shell  turbinate ;  volutions  about  five  (three  of  which  are  shown  in  the  illus- 
tration), rapidly  increasing,  carinated ;  the  last  volution  becoming  ventricose, 
and  marked  by  seven  revolving  carinae,  including  the  one  bordering  the  some- 
what channeled  suture  ;  four  of  the  carinae  are  distinctly  marked  by  thin, 
lanceolate  nodes,  which  become  more  prominent  with  the  increased  growth  of 
the  shell,  while  the  other  three — one  bordering  the  suture  and  two  on  the  lower 
middle  portion  of  the  volution — are  destitute  of  nodes  in  the  specimen  de- 
scribed, but  it  may  be  that  it  assumes  this  character  only  in  an  advanced  stage 
of  growth.  The  carinae  are  situated,  one  at  the  suture  and  one  bordering  the 
moderately  large  umbilicus,  with  five  on  the  body  of  the  volution,  of  which 
two  are  above  the.  middle  and  three  below.  The  spaces  separating  those  bor- 
dering the  suture  and  the  umbilicus  from  those  on  the  body  of  the  volution, 
are  considerably  wider  than  the  .spaces  between  the  intermediate  carinae. 
Aperture  rounded,  slightly  modified  by  the  carinae. 

Surface  marked  by  fine  transverse  striae  of  growth,  which  turn  backward 
as  they  cross  the  volution  to  the  umbilicus. 

The  illustration  on  plate  20  is  a  copy  of  Prof.  Hall's  figure  in  the  27th  Reg. 
Rep.,  and  this  description  also  a  copy  of  Prof.  Hall's  in  the  24th  Reg.  Rep. 
At  the  time  when  my  plates  were  prepared  there  was  only  cne  specimen  of 
this  species  known,  which  belonged  to  the  .cabinet  of  the  late  Dr.  James 
Knapp,  and  which  at  that  time  was  not  accessible  to  me.  Since  then  I  came 
myself  in  possession  of  a  very  fine  specimen  of  this  species,  which  differs  some- 
what from  Knapp's.  Instead  of  having  only  four  carinae  with  nodes,  as  is  the 
case  in  Knapp's  shell,  mine  has  six.  The  only  smooth  carina  in  my  specimen 
is  that  bordering  the  suture.  There  is  also  a  marked  difference  in  the  inter- 
spaces between  the  carinae ;  while  in  Knapp's  shell  the  distance  from  the 
carinae  bordering  the  suture  and  the  umbilicus,  to  their  adjacent  one,  is  larger 
than  the  distances  between  the  other  carinae,  in  my  specimen  the  interspaces 
between  the  first  carina,  as  which  I  count  the  one  near  the  suture,  and  the 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  191 

second,  and  between  this  and  the  third,  are  almost  twice  as  wide  as  any  of  the 
balance.     Outside  of  these  mentioned  differences  there  is  a  complete  resem 
blance  between  the  two  specimens. 

Formation  and  Locality.— Found  in  the  cherty  layers  of  the  Corniferous  limestone,  at  and  around 
the  Falls  of  the  Ohio,  in  Kentucky  and  Indiana.  This  beautiful  fossil  is  exceedingly  rare;  as  far  as  1 
know,  Dr.  Knapp's  and  my  own  specimen  are  the  only  representatives  of  this  species.  Prof.  Hall,  who  first 
described  and  illustrated  this  species  from  Dr.  Knapp's  shell,  named  it  in  honor  of  the  late  Dr.  Lunstbrd 
Yandell,  ST.,  of  Louisville,  Ky.,  who  was  one  of  the  first  collectors  of  the  fossils  at  and  around  the  Falls  of 
the  Ohio. 

Genus  Turbo,    xiem. 

Turbo,  Klein.     Tent.  Meth.  Ostr.— 1753. 
Etymology:  turbo,  meaning  a  top. 

Type  of  this  genus  is  Turbo  marmoratus. 

Shells  turbinated,  solid ;  whorls  convex,  often  grooved  or  tuberculated  ;  aper- 
ture large,  rounded,  slightly  produced  in  front ;  operculum  shelly  and  solid, 
callous  outside,  and  smooth,  or  variously  grooved  and  mammillated  ;  internally 
horny  and  pauci-spiral. 

This  genus  extends  from  the  Silurian  to  the  present  time. 

Turbo  Shlimardi.      De  VERNEUIL. 

Plate  XIX.,  figures  1  to  4,  and  Plate  XXII.,  figures  1  and  2. 
Turbo  shuniardi.   De  Verneuil.     Bulletin  de  la  Soc.  Geol.  de  France. 

Shell  large,  gibbous,  sub-globose.  Spire  moderately  elevated  ;  apex  minute  • 
volutions  about  five  or  six,  gradually  enlarging  in  the  earlier  stages  of  growth, 
while  the  last  one  increases  in  size  very  rapidly,  and  becomes  very  ventricose 
with  an  expanded  aperture.  '  The  first  two  or  three  volutions  are  smooth  and 
regularly  rounded  upon  the  exposed  surfaces,  gradually  becoming  nodose  and 
flattened,  or  somewhat  concave,  on  the  upper  or  front  side.  The  nodes  increase 
in  size  and  strength  with  the  increase  of  the  volutions.  Suture  close  in  the 
earlier  volutions  and  becoming  somewhat  canaliculate  in  the  later  ones.  Lower 
side  of  the  outer  volution  very  convex,  even  in  the  umbilical  region,  and  much 
extended  in  the  direction  of  the  columella.  Aperture  broadly  rounded ;  col- 
umellar  lip  obtuse,  thickened,  having  a  distinct  broad  opercular  groove ;  callus 
covering  the  umbilicus  and  spreading  outwardly  ;  external  margin  of  the 
aperture  thin. 

Surface  marked  by  fine,  comparatively  even  striae  of  growth,  which  are  often 
crowded  into  fascicles,  and  in  old  shells  are  somewhat  imbricated  at  irregular 
intervals. 

The  periphery  of  the  outer  volution  is  marked  by  a  strongly  elevated,  ob- 


192  AL^ONTOLOGY    OF    KENTUCKY. 

tusely  angular  carina,  which  is  continued  from  the  suture-line  at  the  inner 
posterior  angle  of  the  aperture.  The  outer  one  or  two  of  the  volutions  (de- 
pending on  the  size  of  the  shell)  are  marked  or  ornamented  by  strong  curving 
nodes,  which,  commencing  just  below  the  suture,  are  nearly  vertical  for  a  short 
distance,  and  then  curving  forward,  are  finally  directed  towards  the  aperture, 
and  gradually  become  merged  into  the  general  surface. 

The  striae,  originating  at  the  suture,  are  first  directed  backward,  and  thence, 
gently  curving  over  the  nodes,  become  nearly  vertical,  and  thus  continue  to 
near  the  peripheral  carina,  where  they  are  turned  a  little  backward,  and,  pass- 
ing this  elevation,  they  are  directed  with  a  light  curve  towards  the  coin- 
mella. 

This  species  possesses  all  the  features  of  the  Linnaean  genus  Turbo,  to  which 
it  was  originally  referred  by  M.  de  Verneuil,  who  described  and  named  it  in 
honor  of  the  late  Prof.  B.  F.  Shumard,  of  St.  Louis.  It  is  so  very  different 
from  all  other  shells  of  our  rocks,  that  it  will  be  recognized  at  the  first  glance 
by  any  one,  who  has  ever  seen  a  correct  illustration  of  it.  The  shell  is  usually 
silicified,  and  is  rarely  well  preserved  or  occurs  as  internal  casts,  which  bear 
only  slight  indications  of  the  nodes,  but  none  of  the  other  surface-ornamenta- 
tions. 

Prof.  Hall  made  his  descriptions  and  illustrations  from  fine  specimens  be- 
longing to  the  cabinet  of  the  late  Dr.  James  Knapp.  One  of  Knapp's  speci- 
mens was  also  used  for  my  illustrations,  sub-figures  1,  2  and  3,  plate  19.  The 
individual,  of  which  figure  4,  plate  19,  and  figure  2,  plate  22,  are  copies,  is  in 
my  own  collection,  presented  to  me  by  Miss  Spangler,  of  Clark  county,  Indi- 
ana. 

Formation  and  Locality — Found  in  the  rotten  hornstone  of  the  Devonian  formation  in  Jefferson 
county,  Ky.,  and  in  Clark  county,  Ind.  It  is  not  a  very  rare  species,  although  specimens  like  Dr.  Knapp's 
and  my  own  are  extremely  rare. 


MOLLUSCA. 

CEPHALOPODA. 
Genus  Gomphoceras. 

Etymology :  gomphos,  a  club;  keras,  a  horn. 

Gomphoceras  oviforme.    HALL. 

Plate  XXI.,  figures  17  and  18. 

Gomph.  oviforme,  Hall.     Thirteenth  Kep.  N.  Y.  St.  Cab.,  p.  105—1860. 
Oomph,  oviforme,  Hall.     lilust.  of  Dev.  Foss.,  Cephal.,  pi.  45 — 1876. 
Cyrtoceras  gibbosus,  Hall.     Illust.  of  Dev.  Foss.,  Cephal.,  pi.  47 — 1876. 
Oomph,  oviforme,  Hall.     Pal.  N.  Y.,  Vol.  6,  part  2,  p.  344—1879. 

Shell  small,  ovoid,  sub-cylindrical,  straight ;  transverse  section  elliptical  or 
sub-circular ;  longitudinal  section  sub-quadrate  or  sub-ovate.  Plan  of  greatest 
transverse  section  at  the  bottom  of  the  body-chamber.  The  specimens  of  this 
species  found  in  our  rocks  have  retained  only  a  small  section  of  the  septate 
portion  of  the  shell ;  usually  only  one  or  two  septae  are  preserved.  Apex  is 
truncated,  apical  angle  about  sixty  degrees.  Chamber  of  habitation  compar- 
atively large ;  its  length  is  about  equal  to  three-fourths  of  its  largest  diameter  ; 
aperture  large  and  trilobate  (the  one  shown  in  figure  18,  plate  21,  is  incorrect, 
it  is  too  narrow,  and  the  third  lobe,  branching  from  the  middle  to  the  right,  is 
not  at  all  illustrated,  owing  to  the  faulty  condition  of  the  shell  which  served 
for  illustration).  Siphuncle  near  the  ventral  side,  with  a  diameter  of  two  mil- 
limeters at  the  last  septum.  Test  strong,  having  a  thickness  of  one  and  a  half 
millimeters  over  the  chamber  of  habitation. 

Our  specimens  do  not  show  any  surface-markings  ;  if  any  existed  on  perfect 
and  well-preserved  individuals,  they  are  obliterated  on  ours  by  the  process  of 
silicification  and  by  exfoliation.  Our  shells  being  internal  casts,  the  suture  - 
lines  are  plainly  shown.  The  specimen  illustrated  in  figures  17  and  18,  plate 
21,  is  of  average  size  of  those  here  found.  This  species  is  easily  distinguished 
by  its  cylindrical  form,  and  by  the  trilobate  shape  of  its  aperture. 

Formation  and  Locality. — Found  associated  with  its  congener,  Gomph.  turbiniforme,  in  the  chert 
topping  the  hydraulic  limestone  of  the  Devonian  formation,  in  Jefferson  county,  Ky.,  and  Clark  county, 
Ind.,  where  it  is  somewhat  abundant,  but  not  in  fair  specimen. 
GKOI..  SUR.— 25 


J94  PALAEONTOLOGY    OF    KENTUCKY. 

Goinphoceras  turbiniforme.      MEEK  AND  WORTHEN. 

Plate  XXI.,  figures  15  and  1C. 

Gomph.  turbiniforme,  M.  and  W.     Proc.  Acad.  Nat.  Sci.  Phil. — 1860. 
Goynph.  turbiniforme,  M.  and  W.    Geol.  Kop.  of  111.,  Vol.  3,  p.  444—1868. 

Shell  rather  small,  turbinate  or  obovate,  very  slightly  unsymmetrical ;  sec- 
tion circular,  or  nearly  so ;  chambered  part  rapidly  expanding,  with  sides 
slightly  convex  above.  Non -septate  part  very  short,  or  three  times  as  wide  as 
long,  rounding  in  abruptly,  above ;  aperture  contracted,  but  exact  form  un- 
known. Septa  only  moderately  concave,  nearly  equidistant  at  all  points, 
except  near  the  outer  chamber  and  the  apex,  where  they  are  more  crowded ; 
at  about  the  widest  part  of  the  shell,  separated  by  spaces  equalling  one-eighth 
its  greatest  diameter.  Siphon  small  and  marginal.  Surface  nearly  smooth,  or 
with  only  fine  lines  of  growth. 

This  description  is  copied  from  111.  Geol.  Rep.,  Vol.  3,  page  444.  The  speci- 
men there  described  and  figured  on  plate  12,  figures  2a,  b,  came  from  the 
neighborhood  of  the  Palls  of  the  Ohio.  The  specimens  figured  on  my  plate, 
21,  are  of  the  average  size. 

Formation  and  Locality. — FOUR  —  »ue  cherty  layers  superimposed  upon  the  hydraulic  limestone 
of  the  Devonian  formation,  in  Jefferson,  county,  Ky.,  and  in  Clark  county,  Ind. 

Genus  Goniatites,    DeHaan. 

Etymology ;  yonia,  an  angle ;  lithos,  a  stone. 

Goniatites  discoidetis.    HALL. 

Plate  XX.,  figures  14  and  15. 

Goniatites  discoideus,  Hall     13th  Rep.  N.  Y.  St.  Cab.— 1860. 
Goniatites  discoideus,  Hall.    27th  Rep.  N.  Y.  St.  Cab.— 1875. 
Goniatites  discoideus,  Hall,     lllust.  Dev.  Foss.,  pi.  71 — 1876. 
Goniatites  simiosus,  Hall.     Rep.  4th  Dist.  N.  Y.,  p.  246—1843. 
Goniatites  discoideus,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  2,  p.  441—1885. 

Shell  depressed  orbicular  in  the  young  state,  becoming  discoid  in  its  advanc- 
ing growth.  It  differs  in  size,  and  in  the  proportion  of  its  dimensions,  accord- 
ing to  its  age. 

The  specimen  illustrated  shows  the  average  size  of  shells  found  in  our 
rocks. 

A  minute  description  can  only  be  given  by  a  geologist  who  has  a  large 
number  of  specimens  before  him,  some  of  which  he  may  break  or  cut  up,  in 
order  to  see  the  number  of  volutions,  which  are  all  inside  of  the  last  one,  or  to 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROOKS.  195 

examine  other  internal  features.    The  outside  appearance  of  the  shell  offers 
few  points  for  description  which  the  illustration  does  not  plainly  show. 

Formation  and  Locality.— Found  in  the  Corniferous  limestone  of  the  Devonian  formation,  at  and 
around  the  Falls  of  the  Ohio,  in  Kentucky  and  Indiana. 


Genus  Lituites. 

Etymology :  leiuus,  a  trumpet. 

Lituites  marshi.    HALF.. 

Plate  XXX.,  figure  1. 
Liiuiiea  marshi  ,  Hall.     20th  Regent's  Rep.,  p.  362—1867. 

Shell  of  medium  size,  consisting  of  four  or  more  closely  enrolled  volutions, 
which  increase  in  size  gradually,  but  very  slowly,  from  the  apex ;  transverse 
or  cross-section  circular  or  sub-circular  ;  slightly  flattened  on  the  dorsum,  and 
marked  on  the  sides  by  sharp,  strong,  oblique  annulations,  with  regularly  con 
cave  spaces  between  them.  These  ridges,  rising  on  the  ventral  margin,  are 
directed  obliquely  backward  as  they  cross  the  sides  of  the  volutions,  reaching 
the  center  of  the  dorsum  at  a  point  opposite  the  origin  of  the  second  preceding 
one,  having  their  greatest  elevation  on  the  sides  of  the  shell,  and  maJdng  a 
somewhat  abrupt  retrorse  curve,  become  almost  obsolete  on  the  dorsum.  Septa 
moderately  distant,  deeply  and  regularly  concave,  the  chambers  regularly 
increasing  in  depth  with  the  diameter  of  the  shell.  The  space  of  three  cham- 
bers, measured  on  the  side  of  the  shell,  are  equal  to  the  dorso-ventral  diameter 
of  the  volution.  The  dorsal  margins  of  the  septa  are  directed  forward,  giving 
a  broad  rectral  curvature  on  the  side  of  the  volution.  Siphuncle  small  and 
sub-central. 

Surface  of  shell  and  form  of  aperture  are  unknown.  This  beautiful  species 
is  readily  distinguished  by  its  slender  volutions,  and  the  strong,  oblique  ridges, 
which,  in  the  outer  part  of  the  shell,  are  a  little  more  distant  than  the  septa, 
while  on  the  inner  volutions  they  are  nearer  to  each  other,  the  increase  in  the 
distance  of  the  annulations  being  a  little  more  rapid  than  that  of  the  septa. 
Owing  to  the  retrorse  curving  of  the  annulations,  and  the  advancing  curvature 
of  the  septa,  the  ridges  are  cut  by  the  latter  near  the  dorso-lateral  angle  of  the 
volution,  throughout  the  greater  part  of  the  extent  of  shell. 

In  the  specimen  illustrated  on  plate  30,  both  termini  of  the  shell  are  missing  ; 
it  has  preserved  more  than  three  complete  volutions.  The  vacant  central  space 
indicates  that,  probably,  two  full  volutions  are  obliterated  there  at  the  apex. 
How  much  there  is  destroyed  at  the  other  end  can  not  be  ascertained,  but  that 


196  PALEONTOLOGY    OF    KENTUCKY. 

there  is  a  large  part  of  a  volution  missing  can  not  be  doubted.  Thus  it 
appears  that  the  illustrated  specimen,  in  its  perfect  condition,  had  six  full 
volutions.  Prof.  Hall  named  this  species  in  honor  of  Prof.  O.  C.  Marsh,  the 
eminent  geologist. 

Formation  and  Locality. — Found  in  tho  N  iagara  rooks  of  the  quarries  east  of  the  city  of  Louis- 
ville, where  fragments  of  this  shell  are  not  rare,  but  fair  specimens  are  not  often  found. 


NaUtilUS.       Breymus. 

Etymology :  nautilos,  a  sailor  or  navigator. 

Nautilus  maximus.    CONBAD. 

Plate  XXIV.,  figure  1. 

Cyrtoceras  maximum,  Conrad.    Geol.  Survey  of  N.  Y.,  Pal.  Dept.  First  Ann.  Rep. — 1838. 
Nautilus  maximus,  Hall.     Illust.  Dev.  Fossils — 1876. 
Nautilus  maximus,  Hall.    Pal.  N.  Y.,  Vol  6,  pt.  2,  p.  418—1876. 

Shell  very  large,  sub-discoid,  gibbous,  becoming  very  ventricose.  Volutions 
about  three,  contiguous,  not  re-entrant.  Umbilicus  wide  and  deep,  exposing 
all  the  volutions.  Transverse  section  sub  circular,  flattened  on  the  concave 
dorsal  side ;  tube  regularly  and  gradually  enlarging  to  a  point  near  the  aper- 
ture; apical  angle  about  fourteen  degrees.  The  body -whorl,  or  chamber  of 
habitation,  very  large  and  ventricose,  occupying  half  a  volution  and  more.  In 
the  larger  individuals  it  is  free  from  the  inner  volution  for  about  one-third  its 
length. 

Length  of  the  grand  chamber  more  than  twice  its  greatest  diameter,  gradu- 
ally contracting  towards  the  aperture  from  a  point  about  two-thirds  of  its 
entire  length  from  the  base.  Aperture  slightly  oblique  to  the  axis  of  the  tube, 
opening  upward.  Air-chambers  numerous,  regular  and  very  deep,  gradually 
increasing  from  the  apex,  and  measuring  on  the  convex  side  sometimes  more 
than  thirty  millimeters ;  the  last  one  shallower  than  several  of  those  pre- 
ceding. 

Septa  regular,  distant,  very  concave,  the  concavity  greater  than  the  depth 
of  the  air-chambers  ;  strongly  imbricating.  The  distance  between  the  septa  is 
variable  in  different  specimens,  but  in  the  same  individual  is  nearly  constant, 
with  a  gradually  increasing  distance.  Siphuncle  large,  sub-central,  slightly 
expanding  between  the  septa. 

The  ventral  side  of  the  shell  is  indicated  by  a  sharp,  narrow,  longitudinal 
raised  line  on  the  outer  face  of  the  chambers,  on  the  convex  side  of  the  volu- 
tions. Test  seldom  preserved. 


FOSSILS    OP    THE    SILURIAN    AND     DEVONIAN    ROCKS.  197 

Surface  marked  by  fine  and  coarser,  irregular,  lamellose  lines  of  growth,  and 
fine,  regular,  undulating,  elevated,  thread-like  striae,  parallel  to  the  lines  of 
growth ;  longitudinally  marked  by  rounded,  or  sometimes  sharper,  undulating, 
revolving  striae,  of  which  there  are  five  or  six  in  the  space  of  five  millim- 
eters. 

These  markings  are  visible  on  the  macerated  inner  laminae  of  the  shell,  and 
often  even  on  the  internal  cast.  The  internal  cast  is  strongly  marked  by  the 
suture-lines,  which  are  deeply  impressed  from  the  solution  and  removal  of  the 
imbricating  margins  of  the  septa. 

The  largest  known  specimen  of  this  species  has  a  diameter  of  360  millimeters, 
and  the  chamber  of  habitation  of  the  same  specimen,  measured  along  the  mid- 
dle of  the  lateral  face,  has  a  length  of  more  than  360  millimeters,  and  measured 
on  the  periphery,  has  a  length  of  more  than  450  millimeters.  This  species 
resembles  N.  oriens  and  magister,  from  both  of  which  it  is,  however,  easily 
distinguished. 

Formation  and  Locality. — Found  in  the  hydraulic  limestone  of  the  Devonian  formation  at  the 
Falls  of  the  Ohio,  in  Kentucky  and  Indiana.  The  figure  on  plate  24  is  only  one-half  of  the  natural  size 
of  the  shell  from  which  it  was  taken. 


MOLLTJSCA. 

LAMELLIBRANCHIATA. 
Genus  Limoptera.    Han. 

Limoptera,  Hall.     Prelim.  Notice  Lam.  Shells — 1870. 
Etymology :  lima,  a  genus  of  shells;  pteron,  a  wing. 

Shell  large,  inequilateral,  inequivalve ;  the  right  valve  the  smaller  ;  ligamen- 
tal  area  large,  common  to  both  valves ;  longitudinally  striate,  and  extending 
to  the  extremities  of  the  wings.  Margins  of  valves  sinuate  on  the  anterior 
border,  forming  an  elongate  byssal  opening ;  hinge  edentulous  (?).  Anterior 
muscular  impression  situated  within  the  umbones,  very  small  and  deep ;  the 
posterior  one  large,  and  placed  a  little  behind  the  middle  of  shell,  and  nearer 
to  the  hinge  than  to  base  of  valve.  Pallial  line  simple,  formed  of  a  series  of 
small,  deep  pits  (or,  as  seen  in  the  casts,  composed  of  a'  series  of  small 
nodes). 

The  general  form  of  the  shells,  when  well  preserved,  is  broadly  ovate  or 


198  PALEONTOLOGY    OF    KENTUCKY. 

sub-quadrate  in  outline,  strongly  alate  on  the  posterior  side,  and  often  more  or 
less  produced  on  the  anterior  end.  The  valves  are  convex  in  all  species  known  ; 
the  left  valve  being  strongly  convex  throughout,  while  the  opposite  one  is  but 
slightly  elevated,  and  in  one  species  is  somewhat  concave  near  the  base.  The 
surface  is  coarsely  radiate  in  all  but  one  species.  The  ligamental  area  is  large, 
in  both  valves  sub-equal,  and  without  cartilage  pits.  Lima  macroptera  of 
Conrad  may  be  considered  as  type  of  this  genus. 

Limoptera  cancellata.    HALL. 

Plate  III.,  figures  6,  7  and  8;  Plate  IV.,  figure  24. 
Limoptera  cancellata,  Hall.     Prel.  Nat.  Lam.  Shells,  pt.  2 — 1869. 
Limoptera  cancellata,  var.  occidens,  H.  and  W.     24th  Reg.  Rep.,  p.  199 — 1872. 
Limoptera  cancellata,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  1,  p.  244—1883. 

Shell  large ;  body  sub-erect ;  general  outline  very  variable,  from  broadly 
ovate  to  sub-elliptical ;  axis  of  the  body  nearly  vertical  to  the  hinge-line ;  pro- 
portion of  height  to  length  very  variable ;  sometimes  both  dimensions  are  nearly 
equal,  but  mostly  the  height  predominates  over  the  length,  and,  as  shown  in 
our  illustration,  in  some  shells  to  a  considerable  extent.  The  prevailing  form 
may  be  described  as  follows :  Elongate  oviform,  almost  erect,  with  a  slight 
anterior  inclination ;  plano-convex,  with  the  left  valve  strongly  convex  in  the 
umbonal  region,  and  only  moderately  convex,  almost  flattened,  in  its  basal 
half.  The  right  valve  is  entirely  flat,  with  only  a  gentle  elevation  in  the 
umbonal  region.  Height  exceeding  the  length ;  their  proportion  as  four  to 
three. 

The  margins  in  the  lower  or  basal  half  of  the  shell  regularly  curved ;  in  the 
upper  half,  the  anterior  margin  of  the  body  is  only  slightly  rounded,  while 
the  posterior  margin  of  the  body  forms  an  entire  straight  line. 

The  lateral  slopes  of  the  umbonal  region  are  very  steep,  meeting  the  surface 
of  the  wings  almost  at  right-angles,  forming  thus  a  demarcation  line  for  the 
ears.  The  wings  are  unequal,  the  anterior  considerably  smaller  than  the 
posterior.  The  front  wing  forms  only  a  small  triangular  deflection  of  the 
anterior  margin,  while  the  posterior  wing  has  a  considerable  width  on  the 
hinge-line,  and  in  its  longitudinal  dimension  extends  below  the  middle  of  the 
shell.  The  hinge-line  is  usually  straight,  but  sometimes  deflected  in  different 
directions,  as  our  illustration  shows ;  it  is  shorter  than  the  height  or  length. 
The  umbo  of  the  left  valve  is  prominent,  and  the  beak  straight,  rounded  and 
pointed,  and  overreaching  a  small  triangular  hinge-area,  which  has  no  fora- 
men. The  beak  is  situated  about  one-third  the  length  of  the  cardinal  line 
from  its  anterior  end,  and  has  a  decided  anterior  direction.  In  the  right  valve 
the  beak  does  not  extend  beyond  the  cardinal  line.  The  posterior  margin  of 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  199 

the  rear  wing  is  concave,  but  deflects  back  near  the  cardinal  extremity,  which 
is  angular. 

Test  is  of  moderate  thickness,  and  is  ornamented  by  rounded,  abruptly 
elevated  radii,  with  large,  flat  interspaces,  which  are  sometimes  occupied  by 
one  and  even  two  finer,  radiating  striae  ;  but  in  some  shells  these  finer  striae 
are  obsolete.  These  radii  are  crossed,  and  the  large  interspaces  cancellated  by 
fine  concentric  lines  of  growth.  Towards  the  margins,  in  the  basal  half  of 
the  shell,  the  radii  become  either  entirely  obsolete,  or  at  least  very  obscure. 
On  the  wings  the  radiating  striae  are  also  obsolete,  but  .the  concentric  lines  of 
growth  are  there  more  prominent  and  crowded.  On  the  anterior  slope  of  the 
left  umbo  exists  a  curved  line  of  small  and  low  nodules,  numbering  from  ten 
to  twelve  or  more.  This  line  starts  at  the  beak  and  extends  about  an  inch 
towards  the  front.  These  nodes  indicate  small  pits  in  the  interior  surface  of 
the  shell,  and  served,  probably,  as  attachment  for  some  muscles.  The  right 
valve  has  a  similar  line  of  nodes.  The  specimen  here  described  measures  three 
inches  in  height,  two  inches  and  one-fourth  in  length,  and  its  hinge-line  one 
and  three-quarters  inches  long. 

Formation  and  Locality.  —  Occurs  in  the  cherty  layers  superimposed  upon  the  hydraulic  limestone 
of  the  Devonian  formation,  in  Jefferson  county,  Ky.,  and  in  Clark  county,  Ind.,  where  it  is  found  as  a 
silicifled  internal  cast.  Not  rare. 


Meek  and  Wortben. 
Etymology  :  khno,  I  lean  ;  opisthe,  backwards. 

Clinopistha   SUbnaSUta.      HALL  AND  WHITFIELD. 

Plate  IV.,  figures  6,  7,  8  and  12. 

Tellinomya  subnasuta,  H.  and  W.     24th  Reg.  Rep.,  p.  191—1872. 
Dystactella  (Tellinomya)  subnasuta,  H.  and  W.    27th  Reg.  Rep.,  pi.  2—1876.  . 

Shell  small,  elongate,  sub-elliptical,  twice  as  long  as  high,  with  very  ventri- 
cose  valves,  giving  the  shell  in  its  middle  part  a  sub-cylindrical  appearance  ; 
posterior  end  very  narrow,  shorter  than  the  anterior  one,  and  pointed  at  the 
extremity  ;  anterior  end  regularly  rounded,  longest  above  the  center  ;  basal 
line  in  its  central  half  almost  straight,  sometimes  a  little  inflected  opposite  the 
beaks,  or  slightly  convex  ;  Lits  terminal  parts  turn  in  a  gentle  and  regular 
curve  upwards  to  the  anterior  and  posterior  extremities  ;  beaks  small  and 
closely  appressed,  situated  at  two-thirds  of  the  length  of  shell  from  the  an- 
terior end.  Muscular  impressions  of  moderate  size  distinctly  marked,  situated 
near  the  margin  of  valve  ;  pallial  line  entire,  composed  of  a  series  of  radiating 
pustules,  as  seen  on  the  cast. 


200  PALEONTOLOGY    OF    KENTUCKY. 

Surface  marked  by  distinct,  rather  strong,  somewhat  lamellose  lines  of 
growth.  Prof.  Hall  expected  that  this  species  might  not  really  belong  to  the 
genus  Tellinomya,  and  proposed  for  it  the  name  of  Dystactella,  but  placed  it 
afterwards  with  Clinopistha. 

Formation  and  Locality. — In  the  chert  beds  overlying  the  hydraulic  limestone  in  Jefferson  county, 
Ky.,  and  in  Clark  county,  Ind. 

Clinopistha  antiqua.    MEEK. 

Plate  IV.,  figures  9,  10  and  11. 

Clinopistha  antiqua.  Meek.     Proc.  Acad.  Nat.  Sci.  Phil. — 1871. 
Clinopistha  antigua,  Meek.     Geol.  of  Ohio.     Pal.,  Vol.  1,  p,  208 — 1873. 

Shell  transversely  sub-oval,  regularly  and  moderately  convex  ;  height  two- 
thirds  of  the  length,  and  depth  one-half  of  height ;  anterior  end  regularly 
rounded ;  posterior  extremity  only  one-half  as  high  as  the  anterior  one,  nar- 
rowly rounded,  and  most  prominent  below ;  basal  margin  almost  straight,  or  a 
little  inflated  or  slightly  convex,  and  curving  abruptly  upwards  at  the  ex- 
tremities;  beaks  depressed  nearly  or  quite  to  the  dorsal  outline,  small  and 
closely  appressed,  and  placed  at  five-eighths  of  the  whole  length  of  the  shell 
from  its  anterior  end ;  dorsal  line  near  the  beaks  parallel  with  basal  margin, 
but  curving  regularly  into  the  anterior  margin. 

Surface  shows  fine  concentric  lines  of  growth,  but  no  other  markings.  The 
specimen  illustrated  is  of  average  size  and  form.  I  place  this  shell  with 
Meek's  species,  though  my  specimens  are  more  elongate  and  less  gibbous  than 
his. 

Formation  'and  Locality. — In  the  chert  beds  superimposed  upon  the  hydraulic  limestone  of  the  De- 
vonian formation,  in  Jefferson  county,  Ky.,  and  Clark  county,  Ind. 

Clinopistha  striata.    N.  SP. 

Plate  IV.,  figures  1  and  2. 

Shell  of  medium  size,  transversely  sub-elliptical ;  length  not  quite  twice  the 
width  or  height,  and  thickness  about  one-half  the  height;  beaks  small  and 
closely  appressed,  in  the  level  of  dorsal  margin,  and  situated  about  two-thirds 
of  the  whole  length  from  anterior  extremity  ;  basal  margin  slightly  convex  in 
its  central  half,  but  curving  regularly  but  rapidly  into  the  terminal  margins. 
Dorsal  margin  straight  and  almost  parallel  with  the  central  portion  of  the 
basal  one ;  at  its  anterior  end  it  curves  down  into  the  anterior  margin,  which 
appears  to  be  regularly  rounded ;  posterior  end  slopes  down  from  the  beaks  to 
a  somewhat  pointed  posterior  extremity,  which  is  most  prominent  a  little  below 
middle  height  of  the  shell ;  both  valves  are  moderately  convex, 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  201 

The  surface  is  marked  by  very  peculiar  radii,  which,  apparently,  run  from 
the  basal  margin  to  the  dorsal  one,  across  the  valves,  but  which  make,  near  the 
dorsal  line,  a  rapid  deflection  into  the  direction  of  the  beaks.  These  radii  are 
low  and  flat,  and  have  a  faint,  but  plainly  observable  depressed  line  in  their 
middle,  a  feature  which  I  have  never  noticed  in  any  other  shell.  Their  inter- 
spaces are  large,  from  three  to  four  times  of  their  own  width ;  in  some  of 
these  interspaces  there  is  a  smaller  intermediate  line.  This  species  has  the 
general  features  as  Clinopistha  subnasuta  and  antiqua,  except  its  peculiar  sur- 
face-markings, and  its  greater  size.  I  place  it  into  the  genus  Clinopistha,  on 
account  of  its  general  form  agreeing  with  that  of  C.  subnasuta  ;  whether  or 
not  interior  characters  will  leave  it  there  or  transfer  it  to  another  known 
genus,  or  make  a  new  one  for  its  reception,  I  can  not  say.  The  two  specimens 
illustrated  on  plate  4  are  of  average  size,  and  are,  as  far  as  I  know,  the  only 
two  shells  of  this  species  so  far  found.  Both  belong  to  my  own  collection. 

Formation  and  Locality.— Found   in   the  cherty  layers  overlying  tile  hydraulic  limestone  of  the 
Devonian  formation,  in  Jeflerson  county,  Ky.,  and  in  Clark  county,  Ind. 


Genus  Ptychodesma.    Han. 

Ptychodesma,  Hall.     24th  Regent's  Report — 1872. 
Etymology :  ptychos,  a  folding  ;  desma,  a  ligament  or  band. 

Shell  modioloid  in  form ;  valves  equally  convex ;  hinge  with  a  wide  liga- 
mental  area,  the  sides  of  which  are  sharply  grooved  in  parallel  lines,  caused 
by  the  successive  growth  of  the  ligament,  as  in  Pectunculus.  The  grooves  and 
ridges  are  slightly  arched  beneath  the  apex  of  the  valves,  where  they  take 
their  origin. 

The  internal  hinge  structure  is  unknown.  In  general  form  and  characters 
this  genus  resembles  Modiomorpha,  but  differs  in  having  a  ligamental  area 
marked  by  fine  striae  parallel  to  the  hinge-line,  while  this  is  parallel  to  the 
margin  of  the  shell. 

The  type  of  the  genus  is  Ptychodesma  knappiana. 

Ptychodesma  knappiana.        HALL. 

Plate  II.,  figures  13,  15,  16,  17  and  18. 

Ptychodesma  knappiana,  H.  and  "W.     24th  Rep.  N.  Y. — 1872. 
Ptychodesma  knappiana,  Hall.     Pal.  N.  Y.,  Vol.  6,  pt  1,  p.  353—1885. 

Shell  of  medium  size,  obliquely  sub-ovate ;  length  usually  more  than  one- 
third  greater  than  the  height ;  basal  margin  oblique,  often  nearly  straight  in 
the  middle  of  its  length.  Posterior  end  broadly  rounded, 

GEOL.   SUR. — 26 


202  PALAEONTOLOGY    OF    KENTUCKY. 

Cardinal  line  straight,  oblique,  having  a  length  posterior  to  the  beaks  of 
about  one-half  the  length  of  the  shell.  Anterior  end  very  short,  curving 
downward  into  the  basal  margin  without  limitation.  Valves  convex  in  the 
lower  and  posterior  portions  ;  gibbous  in  the  middle  and  above. 

Beaks  sub-anterior,  small,  distant,  closely  incurved,  rising  but  little  above 
the  hinge- line.  Umbonal  slope  presenting  an  undefined  ridge,  which  merges 
into  the  general  convexity  of  the  shell  about  the  middle  of  its  length.  Test 
thick,  marked  by  fine  concentric  striae,  with  distant  imbricating  lamellae. 

Ligamental  area  deeply  excavated,  marked  by  numerous  longitudinal  striae, 
which  are  abruptly  arched  just  beneath  the  beak.  Hinge  with  two  or  more 
cardinal  teeth.  Anterior  muscular  impression  strong. 

Dimensions  of  the  shells  in  this  species  do  not  vary  much.  Figure  16,  plate 
2,  represents  an  individual  of  average  size. 

This  shell  bears  some  resemblance,  externally,  to  some  species  of  Modio- 
morpha  and  Nyassa,  but  its  deeply  grooved  ligamental  area  is  a  distinctive 
feature.  Figure  18,  plate  2,  shows  the  said  area  of  a  left  valve  once  enlarged. 

Formation  and  Locality. — In  the  cherty  layers  of  the  Devonian  limestone,  which  Prof.  Hall  places 
among  the  Hamilton  rocks,  in  Clark  county,  Ind.,  and  in  Jefferson  county,  Ky.  It  is  found  in  well  pre- 
served, silicified  specimens,  but  is  a  rather  rare  species ;  it  is  represented  in  only  a  few  collections  in  the 
Falls  Cities  and  elsewhere.  Prof.  Hall  named  this  species  in  honor  of  the  lamented  Dr.  James  Knapp,  ot 
Louisville,  Ky.,  who  collected  the  first  specimens  of  it,  and  loaned  them  to  Erof.  Hall  for  description  and 
illustration. 

Genus  Conocardium.    Bronn. 

Conocardium,  Bronn.     Lethaea  Geognostica,  Vol.  I.,  p.  92 — 1835. 
Etymology :  konos,  a  cone ;  kardia,  the  heart. 

Type :  Cardium  hybernicum,  Sowerby. 

Shell  equivalve,  inequilateral,  more  or  less  fusiform  or  trigonal.  Posterior 
end  obliquely  truncate,  produced  along  the  cardinal  line  into  a  siphonal  tube, 
and  sometimes  the  antero-inferior  margin  is  also  produced.  Anterior  end 
conical  and  gaping  in  front.  Beaks  prominent  and  strongly  incurved.  Ven- 
tral margins  crenulated  ;  cardinal  line  straight ;  umbonal  ridge  prominent,  and 
ornamented  with  an  expansion  of  the  test  in  continuation  of  the  truncated 
posterior  end. 

Surface  marked  by  concentric  striae,  and  usually  ornamented  with  strong 
radii.  Hinge  with  anterior  and  posterior  laminar  teeth.  Ligament  external ; 
muscular  impressions  two  in  each  valve,  situated  near  the  cardinal  extremities  ; 
pallial  line  simple.  In  the  anterior  end  there  is  a  thickening  or  internal  pro- 
cess forming,  apparently,  a  foot-sheath. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  203 

Conocardium  cuneus.    CONRAD. 

Plate  V.,  figures  10  to  19. 

Pleurorhynchus  cuneus,  Conrad.     Geol.  Surv.  N.  Y.  Ann.  Hep. — 1840. 
Pleurorhynchus  trigonalis,  Hall.     Geol.  Surv.  N.  Y.  Rep.  4th  Dist.,  p.  171 — 1843. 
Conocardium  trigonale,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  1,  pis.  and  exp. — 1883. 
Conocardium  cuneus,  Hall.    Pal.  N,  Y.,  Vol.  5,  pt.  1,  page  409 — 1884. 

Shell  large  ;  shape  very  difficult  to  compare  with  any  generally  known  form  ; 
its  side-view  is  more  or  less  sub-trigonal,  and  its  dorsal  or  ventral  view  angu- 
larly sub-ovate.  The  proportion  of  its  length  to  its  height  varies  considerably  ; 
the  length  is  always  greater  than  the  height,  but  never  becomes  twice  as  large 
as  the  latter. 

The  basal  margin  is  gently  curved  from  the  posterior  extremity  to  the  an- 
terior end.  The  posterior  extremity  is  abruptly  truncated,  and  produced  into 
a  tubular  extension  alone:  the  cardinal  line.  This  tubular  extension  attains, 
in  some  shells,  a  considerable  length,  and  is  supposed  to  serve  as  a  siphuncle. 
The  truncated  rear  end  is  very  large  in  extent,  and  cardiform  in  shape ;  it  is 
usually  concave,  with  the  exception  of  the  part  near  and  around  the  siphuncle, 
which  is  more  or  less  convex. 

Cardinal  line  straight ;  its  margins,  anterior  to  the  beaks,  are  inflected.  An- 
terior end  more  or  less  rapidly  contracting,  with  the  margins  gaping  before 
reaching  the  extremity.  Valves  entirely  equal,  and  more  or  less  gibbous.  The 
beaks  are  prominent  and  closely  incurved  over  the  hinge-line;  they  are  situated 
near  the  center. 

The  umbonal  ridge  is  acutely  angular,  forming  the  line  of  demarcation  be- 
tween the  lateral  and  posterior  surfaces ;  it  extends  from  the  beaks  to  the  pos- 
terior extremity  in  basal  margin.  Test  thick,  composed  of  two  distinct 
layers. 

Surface  marked  by  numerous  radiating  plications,  and  intermediate  arching 
lamellose,  concentric  striae  on  the  body  of  the  shell.  The  posterior  surface 
is  ornamented  by  regularly  curving  radii,  circling  around  the  base  of  the 
siphuncle.  From  the  entire  periphery  of  the  umbonal  ridge  extends  an  ex- 
pansion of  the  shell,  called  the  shield,  increasing  in  extent  from  the  beaks 
downward  to  the  posterior  extremity  of  the  basal  margin.  This  shield  is 
covered  with  fine  striae,  running  parallel  with  the  basal  margin.  In  some 
specimens,  we  notice  at  the  extreme  rear  end  of  the  body  of  the  shell,  where 
the  shield  has  been  removed,  a  long,  slender,  cylindrical  tube  in  the  extension 
of  the  basal  line.  What  purpose  it  serves  is  not  known.  The  valves  are 
finely  crenulated  at  the  margins.  Prof.  Hall  has  united  different  forms,  which 
were  heretofore  considered  different  species,  into  Con.  cuneus ;  he  retains  the 
abandoned  species,  however,  as  varieties,  which  are  as  follows : 


204  PALAEONTOLOGY    OF    KENTUCKY. 

Var.  uttenuatum,  Conrad,  which  are  apparently  only  the  young  of  C. 
cuneus. 

Var.  trigonale,  the  forms  found  in  our  rocks,  and  formerly  always  known 
under  that  name. 

Var.  nasutum,  Hall,  a  short,  very  ventricose,  and  abruptly  truncated  form. 

Formation  and  Locality. — This  shell  is  not  rare  in  our  Devonian  rocks,  at  and  around  the  Falls  ot 
the  Ohio,  where  it  is  often  found  in  the  rotten  hornstone;  but  fair  or  perfect  shells  are  not  often  met  with. 
1  have  figured  on  plate  5  a  small  individual  which  comes  as  near  perfection  as  possible;  it  shows  the 
whole  shell  with  complete  shield,  and  is  a  most  beautiful  but  delicate  fossil.  I  found  it  on  the  Indiana 
shore  of  the  Ohio,  opposite  the  falls. 

Genus  Cypricardinia.    Han. 

Cypricardinia,  Hall.     Pal.  N.  Y.,  Vol.  3,  page  266—1859. 
Etymology  •  Resembling  Cypricardia. 

Shell  being  inequilateral,  with  a  more  or  less  distinctly  defined  oblique  pos- 
terior ridge,  the  umbones  anterior  or  sub-anterior,  and  little  elevated.  The 
surface  is  concentrically  grooved,  or  more  or  less  distinctly  marked  by  promi- 
nent ridges  or  imbricating  lamellae,  and,  on  some  of  them,  these  lamellae  are 
radiatingly  striated  or  cancellated. 

A  single  well-preserved  specimen  shows  no  external  ligamental  area.  In 
some  species  the  posterio-cardinal  margin  becomes  alate  or  sub-alate.  They 
bear  some  general  resemblance  to  Modiolopsis,  but  the  shell  is  apparently 
thicker,  and  is  more  strongly  marked  by  concentric  striae,  and  with  a  less 
conspicuous  anterior  muscular  prominence,  while  the  aspect  and  general  ex- 
pression of  the  shells  are  quite  distinct. 

Cypricardinia  cataracta.     CONRAD. 

Plate  IV.,  figure  3. 

The  illustration  of  this  species  was  made  from  the  only  specimen  which  I 
then  possessed ;  that  shell  was  defective  in  several  places  of  its  margins,  in 
consequence  of  which  the  figure  does  not  show  the  exact  shape  or  form  of  the 
perfect  shell.  I  shall  try  to  correct  this  in  my  description. 

Shell  of  medium  size,  sub-rhomboid-ovate ;  length  one-half  greater  than 
height ;  basal  margin  nearly  straight,  slightly  concave  anterior  to  the  middle. 
Posterior  extremity  abruptly  rounded  below,  and  obliquely  truncate  above. 
Cardinal  line  straight,  oblique.  Anterior  end  very  short,  rounded  below.  Both 
valves  about  equally  convex;  the  right  one,  apparently,  little  more  than  the 
left.  The  left  valve  is  somewhat  compressed  in  its  middle  portion  near  the 
basal  margin,  but  it  becomes  very  convex,  almost  gibbous,  in  its  umbonal 
region. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  205 

Beaks  nearly  anterior,  of  moderate  size,  and  somewhat  elevated  above  the 
hinge-line;  both  incurved,  and  the  right  one  below  the  other.  The  umbonal 
ridge  extends  from  the  beaks  to  the  produced  lower  part  of  the  posterior  ex- 
tremity. It  is  most  convex  at  about  the  middle  of  the  shell,  from  where  it 
slopes  in  a  gentle  curve  to  its  posterior  extremity  ;  towards  the  hinge  it  in- 
creases in  gibbosity.  On  its  dorsal  side  the  umbonal  ridge  has  a  sharp,  angular 
limitation,  separating  what  may  be  called  the  dorsal  incline  from  the  lateral 
area  of  the  valves.  This  umbonal  line  is  acute- angular,  and  runs  be.ow  the 
summit  of  the  ridge,  on  its  dorsal  side,  up  to  the  middle  of  shell  to  the  point  of 
greatest  convexity  ;  from  here  it  occupies  the  summit  and  becomes  more  or  less 
rounded,  losing  its  distinction  entirely  on  the  posterior  third  of  the  shell. 
The  dorsal  incline  is  strongly  inflected  at  and  near  the  beaks,  but  becomes 
convex  for  the  balance  of  its  extent.  On  the  basal  side  of  the  umbonal  ridge 
there  is  a  shallow,  broad  depression,  extending  from  the  beaks  obliquely  across 
the  valves  to  the  middle  of  basal  margin ;  this  concavity  is  more  pronounced 
on  the  left  valve  than  on  the  right. 

The  cardinal  line  is  straight,  and  measures  about  two-thirds  the  length  of  the 
shell.  The  surface  is  marked  by  several  strong  concentric  lines  of  growth. 
This  shell  resembles  C.  indenta,  but  differs  from  it  by  its  shape  and  surface- 
markings. 

Formation  and  Locality. — Found  in  the  Corniferous  limestone  at  the  Falls  of  the  Ohio,  on  the 
Indiana  shore. 

Cypricardinia  cylindrica.    HALL  AND  WHITFIELD. 

Plate  IV.,  figures  13,  14  and  15. 

Cypricardinia  cylindrica,  H.  and  W.     24th  Reg.  Rep.,  p.  190—1872. 
Cypricardinia  cylindrica,  H.  and  W.    27th  Reg.  Rep.,  pi.  11 — 1875. 

Shell  rather  small,  cylindrical ;  extremities  rounded  ;  height  little  more  than 
the  depth,  and  rather  more  than  twice  as  long  as  high ;  beaks  nearly  ter- 
minal, rounded  and  incurved ;  left  valve  scarcely  less  convex  than  the  oppo- 
site ;  umbonal  slope  slightly  angular.  Surface  marked  by  faint,  distant, 
concentric,  lamellose  lines  of  growth. 

This  species  is  more  elongate  and  cylindrical,  less  arcuate,  and  more  equi- 
valve  than  C.  intiata.  The  lamellose  striae  have  never  been  so  strong,  and  are 
more  distant. 

Formation  and  Locality — Occurs  in  the  cherty  layers  superimposed  upon  the  hydraulic  limestone 
of  the  Devonian  formation  in  Jeffersen  'county,  Ky.,  and  in  Clark  county,  Ind.  It  is  a  very  rare  shell,  is 
always  silicified,  and  there  are  only  very  few  specimens  of  this  species  known. 


206  PALEONTOLOGY    OF    KENTUCKY. 

Cypricardinia  inflata,  var.  subequivalvis.    HALL  AND 

Cypricardinia  inflata,  var.  subequivalvis,  H.  and  W.     24th  Regent's  Report,  p.  189 — 1872. 
Cypricardinia  inflata,  var.  subequivalvis,  H.  and  W.    27th  Regent's  Report,  pi.  11 — 1875. 

This  species  is  described  by  Prof.  Hall  from  a  single  specimen  belonging  to 
the  cabinet  of  the  late  Dr.  James  Knapp.  At  the  time  my  plates  were  pre- 
pared, said  specimen  was  missing,  and  as  thus  the  species  was  not  represented 
by  any  known  specimen,  I  omitted  it.  Since  then  I  have  found,  myself,  two 
fair  shells  of  this  species,  and  I  therefore  give  here  its  description. 

Shell  small,  nearly  equivalve,  sub-quadrilateral ;  beaks  terminal ;  cardinal 
and  basal  margins  sub -parallel;  left  valve  slightly  smaller,  less  convex,  and 
straighter  than  the  opposite  ;  the  post-umbonal  slope  distinctly  angular,  while 
on  the  right  valve  it  is  sub-angular  or  rounded. 

Surface  marked  by  about  twelve  to  fourteen  or  sixteen  strong,  equal,  lamel- 
lose,  concentric  ridges.  Prof.  Hall  based  its  name  of  equivalvis  upon  the  fact 
that  in  crushed  specimens  both  valves  appear  equal,  while  good,  not  distorted, 
individuals  show  the  slight  inequality  of  valves  characterizing  the  genus. 

This  shell  resembles  C.  inflata,  Conrad,  but  the  valves  are  more  nearly  equal, 
and  the  right  valve  is  less  inflated. 

Formation  and  Locality. — The  chert  beds  overlying  the  hydraulic  cement  rock  of  the  Devonian 
formation,  in  Jefferson  county,  Ky.,  and  in  Clark  county,  Ind. 


Genus  Cypricardites. 


Conrad. 


Cypricardites,  Conrad.     Ann.  Geol.  Rep.  N.  Y. — 1841. 
Etymology :  resembling  the  Ejenus  Cypricardia. 

Shells  ventricose,  sub-orbicular  or  broad  ovate  in  outline,  with  an  external 
flattened  ligamental  area ;  cardinal  teeth,  four  or  five,  short,  oblique ;  lateral 
teeth,  two  or  more,  oblique;  muscular  impressions  prominent,  anterior  one 
single  ;  pallial  line  simple.  Silurian. 

Synonyms:  Cyrtodonta  and  Vanuxemia  of  Billings,  and  Palaearca  of 
Hall. 

Cypricardites  halli.    N.SP. 

Plate  XX XIV.,  figures  1  to  6. 

Shell  of  medium  size ;  sub-triangular ;  from  moderately  ventricose  to  gib- 
bous ;  both  valves  equally  convex.  Dorsal  line  almost  straight,  rounding  at 
its  extremity  into  the  anterior  and  posterior  margins ;  anterior  margin  slopes 
down  and  backwards  in  a  gentle  curve,  which  is  slightly  inflected,  at  its  center, 
to  the  basal  margin.  The  angle  formed  by  the  average  direction  of  the  an- 
terior margin  with  the  dorsal  or  hinge-line,  measures  about  sixty  degrees. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  207 

The  posterior  margin  slopes  down  from  the  hinge-line,  either  at  right-angles, 
or  deflecting  backwards,  and  forms  a  gentle  curve  ;  the  basal  line  is  very  short, 
and  strongly  curved,  forming  almost  a  linguiforra  extension  of  the  shell ;  its 
most  prominent  point  is  either  entirely  posterior,  or  below  the  center  of  the 
posterior  portion  of  the  hinge-line. 

Both  valves  have  their  maximum  convexity  a  little  above  the  middle  of  the 
shell,  from  where  they  slope  in  a  regular  curve,  which  is  more  or  less  strong, 
according  to  the  greater  or  smaller  gibbosity  of  the  shell,  towards  the  sides 
and  front ;  the  slope  on  the  posterior  side  of  the  umbonal  region  appears  to 
be  somewhat  steeper  than  the  anterior,  causing  the  flattening  of  the  shell  along 
the  upper  half  of  the  posterior  margin,  and  especially  at  the  posterior  cardinal 
angle.  The  umbonal  region  extends  from  the  beak  to  the  base,  and  crosses  the 
valves  in  a  somewhat  diagonal  direction,  terminating  at  the  basal  extremity. 
The  umbones  are  markedly  deflected  towards  the  anterior  end  ;  they  are  only 
moderately  elevated  above  the  hinge-line;  the  beaks  small  and  closely  incurved; 
the  hinge  is  nearer  to  the  anterior  end,  at  about  two-fifths  of  the  whole  length 
from  the  front.  The  size  of  the  species  is  shown  by  the  two  specimens  illus- 
trated on  plate  34,  of  which  one  is  only  moderately  ventricose,  while  the  other 
is  very  gibbous. 

The  surface  is  marked  by  closely  set,  strong,  concentric  lines  of  growth, 
which  are  more  conspicuous  near  the  margins  than  on  the  umbo. 

Formation  and  Locality. — Found  by  me  in  the  Hudson  River  shales  of  Oldham  county,  Ky. 
Outside  of  the  two  specimens  belonging  to  my  own  collection,  I  do  not  know  of  any  others.  To  contribute 
my  mite,  small  as  it  may  be,  to  the  many  well  deserved  honors  of  America's  greatest  geologist  and  palaeon- 
tologist, the  venerable  Prof.  James  Hall,  of  Albany,  New  York,  I  have  selected  his  name  for  this  beautiful 
little  shell. 

Genus  Grammysia.    Devemeun. 

Qrammysia,  De  Verneuil.     Bull.  Soc.  Geol.  France — 1847. 

Etymology :  gramme,  a  line  of  writing;  mys,  a  mussel  shell;  in  allusion  to  the  transverse  furrows  which 
cross  the  valves  from  the  umbones  to  the  middle  of  the  ventral  margin. 

Shells  equi  valve,  inequilateral,  not  gaping,  furnished  with  two  muscular  im- 
pressions of  very  unequal  size;  pallial  line  rounded  posteriorly,  and  united  with 
the  large  muscular  impression  in  such  a  manner  as  to  leave  about  two-thirds  of 
it  outside  of  the  line ;  ligament  external,  much  prolonged  in  the  depression  of 
the  escutcheon. 

Surface  traversed  by  an  oblique  fold  or  rib  extending  from  the  beak  to  mid- 
dle of  the  inferior  border,  and  by  numerous  rounded  concentric  folds.  This  is 
De  Verneuil' s  description,  which  is  improved  upon  by  Prof.  Hall's,  which  is  as 
follows :  Shell  equivalve,  inequilateral,  varying  from  sub  quadrate  to  trans- 


208  PALEONTOLOGY    OF    KENTUCKY. 

versely  elliptical.  Valves  ventricose,  sometimes  inflated ;  beaks  strong,  prom- 
inent and  incurved ;  hinge-line  shorter  than  the  shell,  posterior  to  the  beaks. 
Dentition  obscure,  or  represented  only  by  irregular  folds  on  the  cardinal  line  ; 
ligament  external,  prominent,  extending  from  beneath  the  beaks  to  nearly 
one-half  the  length  of  the  hinge-line.  Cardinal  margin  bordered  by  a  small, 
deep  and  strongly  defined  lunule.  Anterior  and  posterior  muscular  impres- 
sions faintly  marked,  the  latter  much  the  larger ;  pallial  line  not  sinuate  but 
broken  into  points  or  ridges,  strongly  rounded  posteriorly,  and  uniting  with 
the  large  muscular  scar  near  its  anterior  border. 

Surface  of  shell  often  marked  by  an  oblique  mesial  rib  or  fold,  extending 
from  the  beak  to  the  basal  border,  and  by  numerous  strong,  concentric  folds  or 
ridges,  which  are  frequently  obsolete  on  the  posterior  part  of  the  shell.  The 
shells  appear  to  have  been  thin  and  fragile,  and  are  usually  much  crushed  and 
distorted  from  compression. 

Grammysia  gibbOSa.      HALL  AND  WHITFIELD. 

Plate  IV.,  figures  16  to  20. 

Qrammysia,  secunda,  var.  gibbosa,  H.  and  W.    24th  Kep.  on  N.  Y.  St.  Cabinet,  p.  199 — 1872. 
Qrammysia  secunda,  var.  gibbosa,  H.  and  W.     27th  Rep.  on  N.  Y.  St.  Cabinet,  pi.  12 — 1875. 

Shell  of  medium  size,  sub-elliptical.  Proportion  of  length  and  height  vari- 
able, but  the  length  always  less  than  twice  the  height ;  basal  margin  gently 
curved,  with  a  distinct  but  shallow  sinuosity  anterior  to  the  middle,  this  incur- 
vation of  the  basal  border  is  often  very  obscure,  and  in  some  specimens 
entirely  obsolete.  Posterior  extremity  is  strongly  rounded. 

The  cardinal  line  is  straight,  and  measures  about  two-thirds  of  the  length  of 
shell.  Anterior  end  is  short,  and  regularly  rounded.  Valves  entirely  equal, 
moderately  convex  below  and  at  the  posterior  end ;  becoming  gibbous  in  the 
middle  and  above.  Beaks  almost  anterior;  of  medium  size  and  strongly  in- 
curved- and  closely  appressed.  In  some  specimens  the  beaks  of  both  valves 
have  different  elevations  above  the  hinge-line,  one  overlapping  the  other  ;  this 
feature  is  not  natural,  but  the  result  of  some  distortion.  In  perfect  speci- 
mens the  beaks  are  of  even  height,  and  opposite  to  each  other.  The  umbonal 
slope  is  strongly  rounded  and  extends  to  the  posterior  end  of  the  basal  margin. 
A  broad  but  very  shallow  depression  extends  from  the  beaks,  crossing  the 
valves  obliquely,  and  terminates  at  the  basal  sinus,  forming  a  lateral  sinus  and 
producing  the  basal  one.  In  some  specimens  the  lateral  sinus  is  very  obscure 
and  often  entirely  obsolete.  The  basal  sinus  is  dependent  upon  the  lateral 
one;  it  is  well  marked,  where  the  latter  is  plainly  visible,  and  it  becomes 
obliterated,  where  the  latter  is  obsolete. 

Surface  of  the  shells,  which   occur  only  as  internal   casts,    is    marked   by 


FOSSILS    OP    THE    SILURIAN    AND    DEVONIAN    ROCKS.  209 

more  or  less  strong,  concentric  folds  or  elevations,  which  are  angular  on  the 
anterior  part  of  the  shell,  and  become  rounded  and  lower  posteriorly.  They 
increase  in  size  from  the  beak  to  the  margins.  In  size  this  shell  varies  greatly  ; 
the  forms  illustrated  give  the  average  dimensions  of  this  species. 

Professors  Hall  and  Whitlield  consider  it  so  closely  allied  to  Grr.  secunda, 
as  to  make  a  variety  of  that  species ;  but  to  me,  the  differences  between  this 
shell  and  the  mentioned  species  appear  so  pronounced,  that  I  place  it  in  an  en- 
tirely different  species,  retaining  Hall's  name,  "gibbosa." 

Formation  and  Locality. — Occurs  in  the  cherty  layers  topping  the  hydraulic  limestone  of  the 
Devonian  formation,  in  Kentucky  and  Indiana,  at  and  around  the  Falls  of  the  Ohio. 

Genus  Paracyclas.    Han. 

Paracyelns,  Hall.    Geol.  Surv.  of  N.  Y.,  Kep.  of  4th  Dist.— 1843. 
Etymology:  para,  allied  to;  cyclas,  a  genus  of  shells. 
Type:  Paracyclas  elliptica. 

Shell  equivalve,  sub-equilateral,  sub-orbicular  or  broadly  sub-elliptical.  An- 
terior end  regularly  rounded ;  posterior  end  rounded  or  sub-truncate,  some- 
what more  produced  below  than  the  anterior ;  beaks  small  and  low,  generally 
rising  little  above  the  hinge- line. 

Hinge-line  short ;  post-cardinal  slope  more  or  less  defined  by  an  oblique 
furrow  or  depression,  which  sometimes  leaves  the  extremity  sub-alate. 

Surface  concentrically  striated;  sometimes  with  strong  concentric  ridges 
marking  the  exterior. 

Structure  of  hinge  not  fully  observed.  Ligament  supported  on  each  side, 
internally,  by  a  narrow  plate,  and  leaving  in  the  cast  two  diverging  grooves 
directed  forward  from  the  beak.  Muscular  impression  on  the  post-umbonal 
slope.  Pallial  line  parallel  with,  and  a  little  within,  the  margin  of  the  shell. 

This  fossil  possesses  many  of  the  external  characters  of  the  finely  striated 
forms  of  modern  Lucina ;  and  the  distinguishing  characters  are  not  strongly 
marked. 

(Copied  from  Hall's  Lamellibranchiata. ) 

Paracyclas  elliptica.    HALL. 

Plate  II.,  figures  1,  2  and  3. 

Paracyclas  elliptica,  Hall.     Palaeont.  N.  Y.,  Vol.  5,  part  1,  page  440,  plate  72,  figures  23  to  33. 
Lucina  elliptica,  var.  occidentalis,  H.  and  W.     24th  Ann.  Rep.  N.  Y.  St.  Mus.,  page  189. 

Shell  large,  sub-circular  or  broadly  elliptical ;  length  and  height  about  equal. 
Pallial  margin  regularly  curving  from  the  extremities  of  the  hinge.  Cardinal 
line  short,  more  than  one-third  the  length  of  shell,  slightly  arcuate. 

GEOL.   SUR. — 27 


210  PALAEONTOLOGY    OF    KENTUCKY. 

Valves  regularly  convex,  somewhat  regularly  gibbous  in  the  middle.  Beaks 
a  little  anterior  to  the  middle,  small,  appressed,  and  closely  incurved,  rising 
but  little  above  the  hinge-line.  Umbonal  slope  denned  above  by  a  depression 
extending  from  the  beaks  to  about  the  middle  of  the  posterior  extremity,  dis- 
tinctly limiting  the  post-cardinal  slope  of  the  valves. 

Test  thin;  surface  marked  by  fine  concentric  striae,  which  are  sometimes 
aggregated  into  fascicles  at  irregular  distances. 

Ligamental  groove  narrow  and  elongate.  Posterior  muscular  impression 
just  within  the  post-cardinal  margin  and  below  the  ligamental  groove.  Pallia! 
line  parallel  with  the  basal  margin,  marked  in  the  cast  by  a  row  of  elongated 
nodes,  which  are  the  terminations  of  low  ridges  from  above.  Interpallial  area 
pustulose  on  the  cast.  (Hall.) 

This  species  "resembles  Lucina  proavia  of  Goldfuss  to  such  an  extent  that  it 
is  impossible  to  distinguish  the  German  species  from  the  American.  I  have  in 
my  possession  a  large  number  of  perfectly  preserved  specimens  of  our  shells, 
and  two  equally  well  preserved  specimens  of  Lucina  proavia  from  the  old 
country,  but  so  far  none  of  my  geological  friends  has  been  able  to  pick  out 
the  foreign  species. 

Prof.  Hall  says  the  hinge  of  the  German  shell  is  much  more  declining,  and 
the  anterior  end  is  more  elevated  and  sub-auriculate,  as  shown  in  Goldfuss' 
figures.  If  such  a  difference  is  shown  in  the  figures,  which  I  do  not  doubt, 
it  may  be  that  they  were  taken  from  a  peculiarly  formed  specimen  which  did 
not  represent  the  average  form  of  the  species,  or  the  figure  may  not  be  a  cor- 
rect copy  of  the  specimen  from  which  it  was  taken.  Small  differences,  as 
those  marked  out  by  Prof.  Hall,  taken  from  figures,  should  always  be  con- 
sidered doubtful,  and  never  used  without  other  evidences  to  establish  a  new 
species.  I  have  not  the  least  doubt  that,  in  the  course  of  time,  the  identity 
of  P.  elliptica  and  L.  proavia,  will  be  acknowledged  by  all  American  geolo- 
gists, and  the  fossil  will  then  be  known  under  the  name  of  Paracyclas  proavia. 
The  generic  name  Lucina,  has  to  be  dropped  for  other  reasons. 

Formation  and  Locality. — In  the  Corniferous  rocks  of  Kentucky  and  Indiana,  around  and  at  the 
Falls  of  the  Ohio,  where  specimens  of  exquisite  beauty  and  perfection,  with  the  exterior  shell  as  well  as 
internal  casts  are  found. 

Paracyclas  elongata.    u.  SP. 

Plate  II.,  figure  8. 

This  shell  resembles  very  closely  P.  lirata  of  Conrad,  but  it  differs  from  it 
greatly  in  form,  so  much  so,  that  any  one  must  distinguish  the  two  species  at 
the  first  glance.  While  P.  lirata  has  almost  the  shape  of  a  regular  circle, 
this  shell  has  the  form  of  an  ellipse,  in  which  the  larger  axis  exceeds  the 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  211 

smaller  one  considerably.  In  this  shell  the  width  is  only  about  three-fourths 
of  the  length.  It  is  covered  with  strong  concentric  striae,  which  are  sharply 
marked,  almost  all  parallel  to  each  other  and  equidistant.  The  depression  of 
its  dorsal  margin  in  front  of  the  beaks  is  very  conspicuous  ;  the  illustration 
does  not  show  this  at  all,  or  very  faintly.  The  beaks  are  close  to  the  anterior 
margin  ;  the  anterior  slope  is  steep,  while  the  posterior  one  has  only  little  fall. 
The  size  of  this  shell  varies  in  different  specimens ;  it  agrees  generally  with 
that  of  P.  lirata.  Both  valves  are  moderately  convex. 

It  differs  from  P.  lirata  by  its  elongate  shape  and  by  the  position  of  its 
beaks,  which  is  sub-anterior,  while  the  position  of  the  beaks  in  P.  lirata  is 
almost  central. 

Formation  and  Locality. — Found  in  the  cherty  layers  superimposed  upon  the  hydraulic  limestone 
of  the  Devonian  formation,  in  Jefferson  county,  Ky.,  and  in  Clark  county,  Ind.  It  may  be  possible  that 
some  intermediate  forms  exist  which  connect  this  new  species  with  P.  lirata;  but  it  appears  to  me  that 
both  species  are  sufficiently  different  to  guarantee  the  existence  of  the  new  one. 

Paracyclas  lirata.     CONRAD. 

Plate  II.,  figures  4,  5,  6  and  7. 

Posidonia  lirata,  Conrad.     Geol.  Surv.  N.  Y.,  Ann.  Kep. — 1838. 
Paracyclas  lirata,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  1,  p.  441,  pi.  72,  figs.  2-19. 

Shell  of  medium  size,  sub-circular  or  broadly  elliptical ;  length  a  little 
greater  than  height;  margins  regularly  rounded.  Cardinal  lines  short,  less 
than  half  the  length  of  the  shell.  Valves  moderately  convex  below,  becoming 
gibbous  on  the  middle  and  above. 

Beaks  anterior  to  the  center;  small,  appressed,  rising  but  little  above  the 
hinge-line.  Post- cardinal  slope  not  defined. 

Surface  marked  by  fine  concentric  striae,  and  by  strong,  sub-angular,  con- 
centric ridges,  which  are  more  or  less  sharply  defined,  depending  upon  the 
condition  of  the  specimen  and  the  nature  of  the  matrix  in  which  the  fossil  is 
imbedded. 

Ligamental  grooves  distinctly  marked  and  only  moderately  divergent  from 
the  cardinal  margin. 

In  form  this  shell  is  very  like  the  elliptica,  but  considerably  smaller  in  size, 
and  marked  by  more  or  less  distinct,  angular,  concentric  ridges.  It  also  re- 
sembles Lucina  lineata  of  Goldfuss,  from  the  Devonian  formation  in  Germany, 
with  which  it  may  be  found  specifically  identical.  (Hall.) 

The  size  of  this  species  is  very  variable,  as  may  be  seen  from  the  figures  on 
plate  2,  which  are  of  natural  size.  Prof.  Meek,  in  the  first  volume  of  the 
Palaeontology  of  Ohio,  has  figured  and  described  a  Par.  ohioensis,  which  bears 
a  very  close  resemblance  to  Par.  lirata,  and  differs  only  from  the  latter  by  a 


212  PALEONTOLOGY    OF    KENTUCKY. 

flange  attached  to  the  margin  of  the  shell.     It  is  considered  by  some  geologists 
as  identical  with  Par.  lirata. 

Formation  and  Locality. — In  the  Corniferous  limestone  of  the  Devonian  formation  in  Jefferson 
county,  Ky.,  and  in  Clark  county,  Ind.,  where  it  is  found  rather  abundantly,  and  in  well  preserved  speci- 
mens, which  are  always  entirely  silicified. 


Paracyclas  octerlonii.    ».SP. 

Plate  XXXI.,  figure  18. 

The  shell  of  this  species  agrees,  in  every  particular,  with  that  of  the  preced- 
ing species,  except  in  size  and  form.  It  is  considerably  smaller  than  elliptica, 
measuring  somewhat  less  in  width,  and  considerably  less  in  length.  Its  form 
is  peculiar,  having  its  anterior  and  posterior  margins  almost  straight  and  par- 
allel. Orlando  Hobbs,  Esq.,  of  Jeffersonville,  Ind.,  presented  me  with  the 
first  specimen  of  this  species,  and  drew  my  attention  to  its  peculiar  shape, 
which  could  not  be  the  result  of  distortion,  inasmuch  as  the  shell  did  not  show 
the  least  sign  of  any  violence.  Afterwards  I  came  in  possession  of  a  great 
number  of  specimens,  all  of  which  have  exactly  the  same  figure ;  but  I  never 
obtained  forms  which,  as  intermediates,  could  have  connected  them  with  the 
elliptica.  These  differences  are  so  well  marked,  and  appear  to  be  constant, 
and  I,  therefore,  considered  them  sufficient  to  base  upon  them  a  new  species. 
Should  hereafter  such  forms  be  found,  which  will  connect  them  with  the  ellip- 
tica, they  will,  even  then,  retain  at  least  the  character  of  a  variety. 

Most  all  distorted  specimens  of  Par.  elliptica,  which  came  under  my  observa- 
tion, I  found  to  be  compressed  in  the  direction  from  base  to  hinge-line ;  never 
in  the  direction  from  the  front  to  the  rear,  which  is  easily  explained  by  the 
fact  that  the  Lamellibranchiata  generally  rest  upon  the  base  of  their  shell, 
placing  the  hinge  on  top.  Any  compression  will  be  caused  by  the  weight  of 
superimposed  bodies,  and  will  result  in  reducing  of  the  width  and  enlarging 
of  the  length. 

Formation  and  Locality. — This  species  is  found  associated  with  the  preceding  species  in  the  Cor- 
niferous limestone  of  Kentucky  and  Indiana,  at  and  near  the  Falls  of  the  Ohio.  It  is  somewhat  rare,  at 
least  well  preserved  specimens  are  seldom  found.  I  have  named  this  species  in  honor  of  Dr.  John  A. 
Octerlony,  of  Louisville,  Ky.,  who  is  not  only  an  excellent  physician,  but  also  an  ardent  student  of  Natural 
Sciences,  and  especially  of  Geology  and  Palaeontology 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    EOCKS.  213 

Paracyclas  ohioensis,     MEEK. 

Plate  V.,  figure  20. 

Lucina  ohioensis,  Meek.     Proc.  Acad.  Nat.  Sci.  Phil.,  p.  6 — 1871. 

Compare  Posidonia  lirata,  Conrad.     1838,  see  fig.  12,  pi.  2,  13th  Rep.  on  St.  Cab.  of  N.  Y. 
Lucina  (Paracyclas)  ohioensis,  Meek.     Pal.  of  Ohio,  Vol.  1,  p.  199 — 1873. 

Shell  of  less  than  medium  size ;  compressed  or  only  slightly  convex,  and 
more  or  less  nearly  circular,  though  in  some  specimens  greatly  deviating  from 
that  form,  as  is  shown  in  the  specimen  illustrated  on  plate  5,  figure  20 ;  beaks 
small  and  appressed,  and  very  little  elevated  above  the  dorsal  margin;  they 
are  situated  about  in  the  center  of  the  dorsal  border.  The  anterior  margin  is 
rather  abruptly  compressed  above,  just  in  front  of  the  beaks ;  hinge- margin 
short  and  rounding  into  the  posterior  dorsal  outline  ;  posterior  dorsal  slopes 
of  each  valve  marked  by  a  strongly  oblique  sulcus,  extending  from  the  back 
part  of  the  beaks  to  the  upper  portion  of  the  posterior  margin,  to  which  it 
imparts  a  slightly  sinuous  outline  at  its  termination. 

Surface  ornamented  with  small,  more  or  less  regular,  concentric  undmations, 
which  are  most  strongly  defined  on  the  umbones.  The  average  size  of  shells 
belonging  to  this  species  is  represented  in  the  specimen  illustrated  on  plate  5, 
figure  20. 

This  species  is  closely  allied  to  Par.  lirata,  with  which  it  is  considered  iden- 
tical by  some  palaeontologists ;  but  its  peculiar  posterior  dorsal  sulcus  is  such 
a  prominent  feature,  that  it  may  be  regarded  of  sufficient  importance  and 
value  to  base  upon  it  a  separate  species. 

Formation  and  Locality.— It  occurs,  together  with  its  associates  and  congeners,  the  Par.  elliptica} 
lirata,  elongata  and  octerlonii,5n  the  upper  strata  of  the  Devonian  formation,  in  Jefferson  county,  Ky.,  and 
in  Clark  county,  lud.  It  is,  however,  very  rare  in  our  rocks,  where,  so  far,  only  a  few  specimens  have 
been  found. 

Genus  Goniophora.    Phmips. 

Goniophora,  Phillips — 1848. 

Etymology :  gonia,  an  angle;  phoros,  bearing. 

Shell  equivalve,  very  inequilateral,  rhomboidal  or  trapezoidal  in  outline; 
obliquely  truncate  behind  and  rounded  in  front.  Cardinal  line  usually  straight 
and  not  oblique.  Beaks  small,  closely  incurved,  situated  within  or  about  the 
anterior  third  of  the  shell.  Umbo  prominent.  Umbonal  slope  continued  as  a 
strong  angular  ridge  to  the  post-inferior  margin.  The  valves  are  crossed 
obliquely,  sometimes  vertically,  by  a  broad,  undefined  sinus,  extending  from 
anterior  of  the  beaks  to  the  basal  margin,  which  is  usually  slightly  constricted 
at  this  point. 


214  PALAEONTOLOGY    OF   KENTUCKY. 

Surface  marked  by  more  or  less  regular  concentric  striae,  which  may  be  either 
simple  throughout  or  fasciculate  on  the  anterior  portion  of  the  shell.  Some 
species  are  marked  by  strong,  radiating  striae  upon  that  portion  of  the  valves 
between  the  umbonal  ridge  and  the  sinus. 

Hinge  furnished  with  a  strong  oblique  fold  or  tooth  in  the  left  valve,  situ- 
ated just  beneath  the  beak,  and  a  corresponding  depression  in  the  right  valve. 
No  lateral  teeth  have  been  observed.  Ligament  external,  strong;  its  attach- 
ment to  the  shell  is  marked  by  one  or  more  defined  grooves.  Muscular  im- 
pressions two ;  the  anterior  one  deep  and  strongly  marked,  situated  a  little 
anterior  to  the  beak  and  just  within  the  anterior  margin.  Pallial  line  simple, 
continuing  nearly  parallel  to  the  basal  margin  until  it  crosses  the  umbonal 
ridge,  and  recurving  to  the  posterior  muscular  impression,  which  is  large  arid 
shallow,  and  situated  on  the  posterior  cardinal  slope,  sometimes  near  the  mid- 
dle of  length  of  shell. 

This  genus  was  proposed  by  Phillips  in  1848,  as  a  generic  designation  for 
the  original  Cypricardia  cymbiformis  of  Sowerby,  but  without  generic  defini- 
tion or  illustration  of  internal  characters,  and,  so  far  as  known,  the  genus 
has  never  been  heretofore  described. 

Goniophora  truncata.    HALL. 

Plate  IV.,  figures  21,  22  and  23. 

Goniophora  truncata,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  1,  pis.— 1883. 
Goniophora  truncata,  Hall.     Pal.  IS.  Y.,  Vol.  5,  pt.  1,  p.  298—1885. 

Shell  of  medium  size,  in  a  side  and  front  view  sub-triangular,  in  a  dorsal 
view  sub- elliptical.  Length  about  twice  as  great  as  height ;  anterior  end  of 
the  basal  margin  rounded,  middle  portion  slightly  sinuate,  and  the  rear  por- 
tion nearly  straight  or  slightly  curved  to  the  post-basal  extremity ;  posterior 
margin  obliquely  sub-truncate,  slightly  curving.  Cardinal  line  short  and 
straight.  Anterior  end  short  and  rounded.  There  is  a  broad,  shallow  de- 
pression extending  from  the  beaks  obliquely  across  the  valves  to  the  central 
point  of  the  basal  margin ;  this  last  feature  is  only  faintly  expressed  in  some 
specimens,  and  in  others  entirely  obsolete.  Valves  convex  below  the  umbonal 
ridge,  gibbous  in  umbonal  region.  The  area  above  the  umbonal  ridge,  which 
I  called  [in  Cypricardinia  cataracta  the  dorsal  incline,  is  usually  flattened  or 
very  slightly  convex  ;  in  some  shells  it  is  even  concave.  The  beaks  are  entirely 
anterior,  acute  and  incurved ;  in  some  shells  they  are  closely  appressed,  while 
in  others  they  are  separated  by  a  small  interspace. 

The  umbonal  ridge  is  strongly  defined,  forming  a  very  sharp  edge,  separating 
the  lateral  areas  of  the  valves  from  their  dorsal  incline.  Cardinal  line  is  short 
and  straight,  the  umbones  are  more  or  less  prominent  and  somewhat  angular. 
Test  is  of  moderate  thickness,  the  entire  shell  marked  by  stronger  and  finer 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  215 

radiating  and  concentric  striae,  which  differ  in  their  character,  according  to 
the  places  they  occupy.  On  the  baso-lateral  area  of  each  valve  there  are  sub- 
angular,  abruptly  elevated,  concentric  striae  in  their  course  from  the  anterior 
margin  to  the  umbonal  ridge,  where  they  terminate  parallel  to  the  anterior 
and  basal  margins.  These  elevated  striae  have  flat  interspaces  of  different 
width,  sometimes  three  or  four  times  as  large  as  the  striae.  Some  of  these 
interspaces  are  smooth,  while  others  are  occupied  by  one  to  three  finer  striae. 
Between  the  umbonal  ridge  and  the  sinus,  mentioned  above  as  a  shallow 
depression  crossing  obliquely  the  valves,  these  interspacial  finer  striae  become 
more  prominent,  and  some  more  are  added  by  intercalation,  thus  causing  them 
to  appear  somewhat  crowded.  In  this  region,  limited  by  the  umbonal  ridge 
and  the  lateral  sinus,  the  concentric  striae  are  crossed  by  fine,  closely  arranged 
radii,  giving  that  portion  of  the  surface  a  cancellated,  somewhat  rugose  appear- 
ance. This  cancellated  belt  commences  at  the  apical  end  of  the  umbonal  ridge, 
increases  regularly,  but  rapidly  in  width,  until  it  occupies,  in  the  basal  margin, 
the  whole  posterior  half  of  the  shell. 

The  dorsal  incline  is  covered  by  subequal,  rounded,  and  closely  set  radii, 
which  start  from  the  posterior  portion  of  the  cardinal  line,  and  extend  along 
the  cardino-posterior  margins  to  the  umbonal  ridge  ;  they  increase  in  number 
by  bifurcation  and  interpolation. 

I  do  not  know  any  other  Goniophora,  and  can  not,  therefore,  compare  this 
species  with  any  of  its  congeners.  Prof.  Hall  compares  it  with  G.  perangulata 
of  the  Schoharie  grit,  with  which  he  thinks  it  may  be  identical.  In  comparing 
my  specimens  with  his  figures  of  that  species,  it  appears  to  me  that  there  is  a 
vast  difference  between  both  species. 

Formation  and  Locality. — This  shell  occurs  in  the  Corniferous  limestone  of  the  Deronian  forma- 
tion in  Kentucky  and  Indiana,  at  and  around  the  Falls  of  the  Ohio.  It  is  a  very  rare  shell ;  the  two 
specimens  in  my  own  collection  are,  so  far,  the  only  individuals  found  in  our  rocks. 

Genus  Modiomorpha.    Han. 

Modiomorpha,  Hall.    Prel.  Notice  of  Lam.  Shells — 1870. 

Etymology :  Contracted  from  modiola,  a  genus  of  shells ;  and  morphe,  form  or  shape  like  Modiola. 

Shell  inequivalve,  very  inequilateral,  compressed,  sub-ovate  in  outline, 
largest  posteriorly;  beaks  small,  compressed,  usually  situated  within  the 
anterior  third  of  the  length.  Surface  of  shell  marked  by  rugose  or  undulating 
concentric  striae,  which  usually  coalesce  or  become  fasciculate  toward  the 
anterior  end.  The  valves  are  crossed  obliquely  by  a  more  or  less  distinctly 
defined  sinus  passing  from  the  beak  to  the  base,  and  constricting  the  basal 
margin ;  the  anterior  end  is  rounded,  forming  a  projecting  lobe  of  greater  or 
less  extent  beyond  the  beak.  Hinge  characterized  by  a  single,  strong,  wedge- 


216  PALEONTOLOGY    OF    KENTUCKY. 

form  tooth  in  the  left  valve,  and  a  corresponding  cavity  in  the  right ;  no  lateral 
teeth  exist.  Anterior  muscular  impression  sub-circular,  situated  within  the 
anterior  extension  of  the  shell ;  posterior  impression  large  and  superficial,  sit- 
uated near  the  cardinal  border ;  pallial  line  entire.  Ligament  external, 
attached  to  the  thickened  margin  of  the  shell. 

This  genus  is  allied  to  Modiola,  Modiolopsis  and  Cypricardites,  but  differs 
from  Modiola  in  the  toothed  hinge ;  from  Modiolopsis  in  not  having  lateral 
teeth,  and  from  Cypricardites  in  general  aspect.  Modiomorpha  concentrica 
may  be  considered  the  type  of  this  genus. 

Modiomorpha  affinis,    HALL. 

Modiomorpha  alia,  in  part  (Conrad),  Hall.    Pal.  N.  Y.,  Vol.  5,  part  1,  Plates  and  Explanations  pi.  37,  figs 

13  and  14—1883. 
Modiomorpha  affinis,  Hall.     Pal.  N.  Y.,  part  1,  page  284—1885. 

Shell  large,  robust,  obliquely  ovate,  arcuate ;  length  about  one-third  greater 
than  the  height;  basal  margin  straight  or  slightly  arcuate,  curving  rather 
abruptly  both  at  the  anterior  and  posterior  extremities;  posterior  margin 
abruptly  curving  below  and  more  gently  forward  to  cardinal  margin  ;  cardinal 
margin  arcuate  from  the  beaks  to  the  post-cardinal  extremity.  Anterior  end 
short,  scarcely  denned ;  narrow,  declining  from  the  hinge-line  and  regularly 
rounded  below. 

Valves  convex,  very  gibbous  in  the  middle  and  umbonal  region  ;  depth  more 
than  half  the  height  of  shell.  The  umbonal  elevation  extends  from  the  beaks, 
curving  above  the  middle  to  near  the  post-basal  margin,  forming  an  undefined 
arcuate  ridge. 

Hinge-line  oblique,  extending  more  than  one -third  the  length  of  the  valves. 
Beaks  small,  sub-anterior,  and  closely  incurved. 

Test  comparatively  thick,  marked  by  fine  concentric  striae,  which  are  fascicu- 
late and  pass  into  strong  abrupt  ridges  upon  the  umbonal  and  anterior  portions 
of  the  shell.  Interior  unknown. 

An  individual  of  average  size,  among  the  specimens  of  this  species  in  my 
collection,  measures  as  follows :  length,  twenty -one  lines ;  height,  sixteen  lines, 
and  thickness,  eleven  lines. 

This   form  resembles  Mod.  alta,  but  is  more   elongate,  distinctly  arcuate ; 
the  anterior  end  is  narrower  below  the  beaks ;  the  posterior  end  is  more  pro- 
duced, and  curving  more  abruptly  forward  in  the  upper  part,  with  the  post 
cardinal  angle  rounded.     The  anterior  end  is  less  produced  than  in  typical 
forms  of  Mod.  mytiloides. 

Formation  and.  Locality. — Found  in  the  cherty  layers  superimposing  the  hydraulic  limestone  of 
the  Devonian  formation,  in  Jefferson  county,  Ky.,  and  in  Clark  county,  Ind.  Almost  all  my  specimens  01 
this  and  other  species  of  Modiomorpha  were  found  in  the  cement  quarries  at  "Watson  Station,  in  Clark 
county,  Ind.,  about  six  miles  distant  from  the  Falls  of  the  Ohio, 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    BOOKS.  217 

Modiomorpha  alta.    CONRAD. 

Plate  XXVI.,  figure  10. 

Cypricardites  alta,  Conrad.     Geol.  Surv.  N.  Y.,  Ann.  Rep.,  p.  52 — 1841. 
Modi oinorpha  alia  (Conrad),  Hall.     Prelim.  Notice  Lamellib.  2,  p.  75 — 1870. 
Modiomorplw  alia  (Conrad),  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  1,  pi.  and  exp. — 1883. 
Modwmarpha  alta,  Hall.    Pal.  N.  Y.,  Vol.  5,  pt.  1,  p.  278—1885. 

Shell  above  medium  size,  broad,  rhomboid-ovate;  length  about  one-third 
greater  than  height ;  the  basal  margin,  for  two-thirds  of  its  length  from  the 
anterior  curve,  is  nearly  straight,  varying  from  slightly  concave  to  nearly 
straight,  abruptly  curving  at  the  post-basal  extremity,  and  continuing  to  the 
post-cardinal  margin  in  an  oblique,  gently  curved  line.  In  some  examples, 
the  posterior  margin  is  regularly  curved,  cardinal  margin  sometimes  forming 
a  nearly  straight  line,  usually  gently  arcuate.  Anterior  end  produced  beyond 
the  beak  from  one-sixth  to  one-fourth  the  length  of  the  shell ;  obliquely  trun- 
cated, obtuse,  rounded  below;  its  greatest  extension  is  below  middle  of  the 
shell. 

Valves  convex,  gibbous  on  the  umbonal  and  medial  portion  of  the  shell ;  the 
umbonal  ridge  is  gibbous  and  arched  upward  ;  the  point  of  greatest  convexity 
is  about  the  middle  of  the  shell  or  a  little  posterior.  The  depth  of  both  valves 
is  equal  to  two-thirds  of  the  height  of  the  shell. 

Hinge-line  straight,  oblique,  extending  for  less  than  half  the  length  of  the 
shell.  Beaks  rounded,  somewhat  appressed,  directed  forward.  Umbonal 
region  not  strongly  defined,  depressed  anteriorily,  becoming  gibbous  in  the 
middle  of  the  shell,  gradually  merging  into  the  general  contour  in  the  pos- 
terior portion. 

Test  of  moderate  thickness,  marked  by  irregular  concentric  striae,  which 
become  fasciculate  and  produce  strong  concentric  ridges  at  irregular  intervals. 
The  surface  is  marked  by  fine  vascular  lines,  similar  to  those  on  Mod.  mytil- 
oides.  The  anterior  muscular  impression  is  situated  close  to  the  anterior 
margin  of  rthe  shell,  with  a  small  retractor  scar  above  it.  Other  characters 
of  the  interior  unknown. 

The  specimen  illustrated  on  plate  26,  figure  10,  is  rather  shorter  than  the 
average.  An  individual  of  average  size  has  the  following  dimensions :  length, 
twenty-three  lines  ;  width,  fifteen  lines,  and  thickness,  ten  lines. 

This  species  has  a  greater  proportional  height  than  Mod.  mytiloides,  a 
broader  and  often  sub-truncate  posterior  end,  while  the  anterior  end  is  usually 
broader  and  less  extended  ;  the  umbonal  ridge  is  arcuate  ;  in  other  features  it 
is  very  similar.  In  some  of  its  conditions  this  species  is  not  easily  distin- 
guished from  Mod.  mytiloides. 

Formation  and  Locality. — Pound  associated  with  Mod.  ooncentrica,  mytiloides  and  affinis,  in  the 
cherty  strata  topping  the  hydraulic  limestone,  in  Jefferson  county,  Ky.,  and  Clark  county,  Ind. 
OKOL.  SUR. — 28 


218  PALAEONTOLOGY    OF    KENTUCKY. 

Modiomorpha  charlestowuensis.    v  M-. 

Plato  V.,  figures  7,  8  and  9. 

The  shell  illustrated  on  plate  5,  figures  7,  8  and  9,  has  evidently  its  valves 
dislocated.  The  right  valve  is  more  than  one-eighth  of  an  inch  removed  back- 
ward. 

Shell  of  about  medium  size,  elongate,  sub-elliptical,  very  ventricose  or  gib- 
bous; greatest  height  at  about  one- third  of  length  from  the  anterior  extremity  ; 
valves  strongly  convex,  the  greatest  convexity  being  a  little  anterior  to  the 
middle  of  shell.  Hinge-line  oblique,  almost  straight,  and  of  about  one-half 
the  length  of  shell.  Beaks  anterior  or  sub-anterior,  acute  and  closely  ap- 
pressed.  Umbonal  region  strongly  convex,  angular,  and  inflected  on  its  dorsal 
slope  near  the  beaks,  regularly  curved  on  its  ventral  and  posterior  slopes,  and 
also  in  the  posterior  half  of  its  dorsal  slope ;  prominently  ridged.  The  course 
of  the  umbonla  ridge  forms  an  acute  angle  with  the  cardinal  line,  and  runs 
somewhat  diagonally  to  the  posterior  extremity,  where  the  post-ventral  and 
post-dorsal  margins  meet  in  a  very  abrupt  curve. 

Ventral  or  basal  line  almost  straight,  only  slightly  incurved  in  its  central 
portion ;  at  its  posterior  end  it  curves  regularly  and  gently  upwards  into  the 
abrupt  curve  at  the  posterior  extremity.  The  posterior  part  of  the  dorsal  line 
forms  a  gentle  regular  curve  from  posterior  end  to  hinge-line 

Anterior  end  short,  its  margin  straight  and  sloping  almost  rectangular  with 
the  cardinal  line  down  to  the  basal  margin,  which  it  meets  in  a  short  curve. 

Surface  covered  by  fine  concentric  lines  of  growth,  which,  at  irregular  inter- 
vals, have  been  raised  into  imbricating  lamellae,  leaving  strong  varices  on  the 
cast. 

A  portion  of  the  shell  remaining  shows  the  concentric  lines  as  closely  set  as 
on  Mod.  concentrica,  and  if  the  form  of  my  shell  did  not  differ  so  greatly  from 
that  of  Mod.  concentrica,  I  would  have  placed  it  with  that  species.  Its  elon- 
gate form,  its  great  gibbosity,  its  linguiform  posterior  end,  and  the  marked 
concentric  zones  on  its  surface,  distinguish  it  from  its  other  congener,  with 
which  it  is  associated  in  our  rocks. 

Formation  and  Locality. — The  chert  beds  over  the  hydraulic  limestone  of  the  Devonian  formation 
in.  Jefferson  county,  Ky.,  and  in  Clark  county,  Ind. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  219 

Modiomorpha  concentrica.    CONRAD. 

Plato  II.,  figures  9,  10,  11,  12  and  14. 

Plerinea  concentrica,  Conrad.    Geol.  Surv.  N.  Y.,  Ann.  Rep.,  p.  116—1838. 
Cypricarditcs  concentrica,  Conrad.     Geol.  Surv.  .N.  Y.,  Ann.  Rep ,  p.  52 — 1841. 
Cypricardites  oblonga,  Ibidem. 

Modiola  concentrica,  Hall.     Geol.  Surv.  N.  Y.,  Rep.  4th  Dist.— 1843. 
Modiomorpha  concentrica,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  1,  p.  275—1885. 

Shell  of  medium  size,  ovate,  extremely  variable  in  its  proportions ;  length 
less  than  twice  the  height ;  basal  margin  often  nearly  straight,  usually  a  little 
concave  on  the  anterior  one-third ;  posterior  margin  rounded  abruptly  below, 
but  gently  curving  above.  Cardinal  margin  oblique  in  the  prevailing  forms, 
moderately  arcuate,  often  nearly  straight ;  sub-alate  in  many  specimens.  An- 
terior end  produced  beyond  the  beaks,  many  specimens  only  slightly,  abruptly 
rounded,  sometimes  nasuate,  limited  by  a  broad  depression  extending  from  the 
beak  to  about  the  anterior  third  of  the  basal  margin.  In  our  Kentucky  shells 
the  shape  differs  as  regards  the  anterior  end,  which  is  not  at  all,  or  at  least 
only  slightly  produced  beyond  the  bend;  the  anterior  margin  is  almost  straight 
or  little  curved,  and  turns  at  the  beaks  abruptly  down  to  the  basal  margin. 

Valves  moderately  convex,  but  somewhat  gibbous  along  the  umbonal  slope ; 
the  point  of  greatest  convexity  is  about  one-third  of  the  length  from  the  an- 
terior margin.  Hinge-line  extends  generally  to  the  middle  of  shell,  sometimes 
even  beyond  the  same. 

Beaks  sub-anterior  (in  our  western  shells  anterior),  small,  sharply  angular, 
appressed,  directed  forward.  Umbonal  region  a  more  or  less  prominent  sub- 
angular  elevation,  extending  obliquely  from  beak  towards  the  post-basal 
margin,  but  usually  dying  out  about  the  middle  in  the  length  of  the  shell. 

Test  comparatively  thick,  and  ornamented  by  concentric,  rounded  or  sub- 
angular  striae,  which  become  lamellose  and  coalescing  on  the  anterior  end  of 
the  valves,  where  they  are  less  prominent. 

Anterior  muscular  impression  strong,  striated,  situated  just  within  the 
anterior  margin,  with  a  small  retractor  scar  above  it.  Posterior  impression 
large  and  shallow.  Pallial  line  moderately  impressed.  Hinge  furnished  with 
a  strong  cardinal  tooth  just  posterior  to  the  beak  in  the  left  valve,  and  a 
corresponding  depression  in  the  right  valve.  No  proper  lateral  teeth  have 
been  observed,  but  the  cardinal  margin  is  thickened  and  grooved  from  the 
beak  backward  about  half  the  length  of  the  cardinal  line.  It  is  impossible  to 
give  in  figures  the  dimensions  of  the  different  individuals,  nor  the  different 
sizes  of  the  specimens.  The  proportion  of  length,  width  and  thickness  is  as 
variable  as  the  sizes  of  the  different  shells.  The  illustrations  on  jjlate  2  give 
the  sizes  of  average  specimens. 

Formation  and  Locality. — Found  associated  with  Ptyohodesma  knappiana  in  the  oherty  layers 
of  the  Devonian  limestone,  in  Jefferson  county,  Ky.,  and  in  Clark  county,  Ind.,  at  and  around  the  Palls  of 
the  Ohio.  It  occurs  rather  abundantly  in  fractional  shells,  but  fair  specimens  are  not  often  met  with. 
The  shell  illustrated  by  figure  14,  plate  2,  has  two  beautiful  orania  attached  to  its  surface. 


220  PALEONTOLOGY    OP    KENTUCKY. 

Modiomorpha  mytiloides.    CONRAD. 

CypricarditiS  mytiloides,  Conrad.     Geol.  Surv.  M.  Y.,  Ann.  Rep. — 1841. 

Modiomorpha  complanata,  Hall.     In  err.  Pal.  N.  Y.,  Vol.  5,  pi.  1,  plates  and  explanations,  pi.  38,  figures 

1-16—1883. 

Modiomorpha  planulala,  Hall.     Prelim.  Notice  Lamellib.  2,  p.  74 — 1870. 
Modiomorpha  mytiloides,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  1,  p.  277—1885. 

Shell  larger  than  medium  size,  rhomboid- ovate,  oblique ;  length  less  than 
twice  the  height ;  basal  margin  nearly  straight,  or  very  slightly  concave  ante- 
rior to  the  middle,  curving  to  anterior  and  posterior  extremities;  posterior 
margin  abruptly  curving  below,  and  more  gently  recurving  toward  cardinal 
line ;  cardinal  margin  arcuate.  Anterior  end  narrow,  extended,  abruptly 
curved  on  the  margin ;  somewhat  defined  by  the  sinus,  which  extends  from 
anterior  of  the  beak  to  the  middle  of  the  shell. 

Valves  moderately  convex,  in  old  shells  gibbous  in  the  umbonal  region. 
Hinge-line  oblique,  extending  to  about  the  middle  of  length  of  shell. 

Beaks  appressed,  situated  a  little  more  than  one-fourth  the  length  of  shell 
from  anterior  end.  Umbonal  region  not  defined;  convex  in  young  specimens, 
becoming  more  gibbous  in  older  ones. 

Test  of  moderate  thickness,  concentrically  striated  with  irregular  lines  of 
growth,  which  are  sometimes  elevated  into  concentric  ridges.  The  post-cardi- 
nal slope  in  well-preserved  specimens  shows  fine  vascular  markings.  The  an- 
terior muscular  impression  is  well  marked,  and  situated  just  within  anterior 
margin  below  beak.  Other  interior  characters  are  not  known. 

An  average  sized  individual  of  this  species  has  the  following  dimensions : 
length,  twenty-six  lines ;  width,  seventeen  lines,  and  thickness,  ten  lines. 

This  species  resembles  somewhat  in  form  Mod.  concentrica,  but  its  anterior 
end  is  more  produced,  and  it  does  not  show  the  concentric  striae  of  that 
species.  It  also  resembles  some  forms  of  Mod.  alta,  but  is  more  elongate,  and 
possesses  a  more  regularly  rounded  posterior  extremity,  and  a  narrower  an- 
terior end. 

Formation  and  Locality. — Occurs  in  the  chert  of  the  Devonian  formation  in  Jefferson  county,  Ky., 
and  in  Clark  county,  Ind.,  in  company  with  its  congeners,  Mod.  concentrica,  alta  and  affinis.  Watson's 
Station,  in  Clark  county,  Ind.,  on  the  Ohio  and  Mississippi  Railroad,  furnishes  fair  specimens  in  a  silicified 
condition. 


Genus  Nucula. 


Lamarck. 


Nucula,  Lamarck.     Hist.  Nat.  Des.  An.  Sans  Vert. — 1815. 
Etymology:  nucula,  a  little  nut. 

Shell  small,  equivalve,  inequilateral,   trigonal  or  transversely  elliptical  or 
sub-circular.      Anterior  or  posterior  extremity  sometimes  produced,   usually 


FOSSILS    OF    THE    SILURIAN    AND     DEVONIAN    ROCKS.  221 

rounded.  Beaks  anterior  or  posterior  to  the  middle  of  the  length,  often  sub- 
central.  Cardinal  line  arcuate  ;  escutcheon  marked.  Surface  marked  by  con- 
centric striae,  which,  in  some  species,  are  regular  and  rugose. 

Hinge  furnished  with  a  triangular,  spoon-  shaped  cartilage-pit  beneath  the 
beaks,  with  a  series  of  small  transverse  teeth  on  each  side.  There  are  two 
principal  muscular  impressions  in  each  valve,  with  usually  a  smaller  retractor 
scar  adjacent,  and  also  the  cavity  of  the  beaks  often  shows  several  pits  for  the 
attachment  of  umbonal  muscles.  Pallial  line  simple. 

Examples  :  Nucula  varicosa  and  N.  randalli.  (Copied  from  Hall's  Lamelli- 
branchiata.) 


NUCUla.       Lamarck. 
Etymology  :  nucula,  a  little  nut. 

Nucula  herzeri.    N.SP. 

Shell  small,  elongate,  sub-  trigonal  ;  very  gibbous.;  length  one  and  one-half 
the  height  ;  both  terminal  extremities  very  narrow,  almost  pointed  ;  beaks 
prominent  and  closely  incurved  ;  situated  about  one-fourth  of  the  whole  length 
from  the  anterior  end  ;  basal  margin  in  its  main  portion  only  slightly  convex, 
even  at  its  anterior  end,  where  it  joins  the  anterior  margin,  which  is  most 
prominent  close  to  the  basal  line  ;  at  the  posterior  end  the  basal  margin  turns 
in  a  light  regular  curve  upwards  to  the  very  narrow,  often  pointed,  posterior 
margin.  The  cardinal  margin  slopes  in  a  straight  line  down  to  the  posterior 
extremity,  and  with  an  inflected  curve  very  abruptly  to  the  anterior  extremity  ; 
umbones  very  ventricose,  making  the  thickness  of  the  shell  equal  to  its 
height. 

This  species  is  associated  with  Nuc.  niotica  and  neda,  which  it  resembles  in 
some  points,  but  is  easily  distinguished  from  them  by  its  elongate  form,  its 
pointed  terminal  extremities,  and  the  equality  between  its  depth  and  height. 
An  average-sized  specimen  of  this  species  has  the  following  dimensions:  length, 
one-half  inch;  height  and  depth,  one-  third  of  an  inch. 

Formation  and  Locality.  —  Occurs  in  the  cherty  layers  overlying  the  hydraulic  cement  rock  of 
the  Devonian  formation  around  the  Falls  of  the  Ohio  in  Kentucky  and  Indiana,  I  dedicate  this  pretty 
little  shell  to  Rev.  H.  Herzer,  formerly  of  Louisville,  Ky.,  who  devoted  his  spare  time  to  the  study  of 
Natural  Sciences,  and  especially  to  that  of  Palaeontology.  It  was  'he  who  rekindled  in  me  the  love  for 
Geology,  which  was  almost  extinguished  by  many  years  of  hard  work,  but  which  since  has  afforded  to  mo 
so  many  hours  and  days  of  genuine  enjoyment. 


222  PALEONTOLOGY    OF    KENTUCKY. 

NuCUla  neda,      HAM.  AND  WIIITKIKLD. 

Plate  V.,  figures  5  and  6. 

Nucula  neda,  H.  and  W.     24th  Eeg.  Kep.,  p.  191—1872. 
Nucula  neda,  H.  and  W.    27th  Reg.  Rep.,  pi.  11— 1875. 

Shell  cuneiform,  sub-trigonal,  with  the  umbones  ventricose ;  the  beak  a 
little  more  than  one-third  from  the  anterior  end,  prominent  and  incurved. 
Cardinal  margin  sloping  to  the  anterior  and  posterior  extremities  ;  basal  mar- 
gin straight. 

The  «ast  shows  strong  anterior  and  posterior  muscular  impressions,  with 
three  or  four  umbonal  muscular  scars ;  a  narrow  pedal  scar  just  within  the 
cardinal  line,  anterior  to  the  posterior  muscular  area,  as  usual  in  the  genus 
Nucula. 

The  surface  has  been  marked  by  fine  concentric  lines  of  growth.  It  is  asso- 
ciated with  Nucula  niotica,  which  it  resembles  in  many  features,  but  it  differs 
from  it  in  several  points,  which  are  given  in  the  description  of  that  species. 

Formation  and  Locality. — Occurs  in  the  chert  beds  superimposed  upon  the  hydraulic  limestone  of 
the  Devonian  formation,  around  the  Falls  of  the  Ohio,  in  Kentucky  and  Indiana. 

NllCllla  niotica.      HALL  AND  WHITFIELD. 

Plate  V.,  figures  2,  3  and  4. 

Nucula  niotica,  H.  and  W.     24th  Regent's  Rep.,  p.  190 — 1872. 
Nucula  niotica,  H.  and  W.     27th  Regent's  Rep.,  pi.  11—1875. 

Shell  small,  obtusely  cuneiform;  the  beaks  prominent,  incurved,  with  the 
umbo  inflated  ;  height  from  beak  to  base  equal  to  three  fourths  the  length  of 
the  shell.  Surface  marked  by  fine,  even,  concentric  striae,  with  sometimes 
strong  varices  of  growth.  The  internal  casts  show  the  evidence  of  strong, 
anterior  and  posterior  muscular  im  pressions,  and  three  distinct  umbonal  pedal 
muscles,  seven  or  more  posterior  and  five  anterior  teeth  in  a  specimen  of  me- 
dium size.  Hall's  description. 

We  find  three  distinct  Nucula  in  our  rocks;  two  of  the  species  have  a  cunei- 
form sub- trigonal  form,  as  shown  in  Prof.  Hall's  figures  of  Nucula  neda  and 
niotica;  they  must,  therefore,  be  the  two  species  in  question ;  but  which  is  neda 
and  which  is  niotica?  Prof.  Hall's  descriptions  and  figures  of  both  species  may 
answer  to  either  one.  There  is  only  one  point  in  the  descriptions  which  may 
decide  the  question ;  this  is  the  character  of  the  respective  umbones.  Accord 
ing  to  Hall,  the  umbo  of  N.  niotica  is  inflated,  and  the  umbo  of  the  neda  is 
ventricose.  Basing  my  identification  of  the  two  species  upon  this  single  point 
of  difference,  I  will  try  to  point  out  a  few  more  distinguishing  features.  Nu- 
cula niotica  differs  from  Nucula  neda  in  the  following  characters : 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  223 

1.  In  N.  niotica  the  umbo  is  inflated,  in  .Nucula  neda  it  is  very  ventricose. 

2.  In  N.  niotica  the  depth  is  only  one-half  of  the  depth  of  neda,  measured 
in  specimens  of  the  same  size,  at  the  point  of  their  greatest  convexity. 

3.  In  !N.  niotica  both  slopes  of  the  beaks  are  concave,  while  those  in  N.  neda 
are  almost  straight. 

4.  In  N.  niotica  the  basal  margin  is  broadly  curved,  while  that  of  N.  neda  is 
straight  or  even  inflected. 

Formation  and  Locality. — Irrthe  chert  beds  over  the  hydraulic  limestone  of  the  Devonian  forma- 
mation,  in  Jefferson  county,  Ky.,  and  in  Clark  county,  Ind.  Pound  in  silicified,  fairly  preserved  speci- 
mens; not  very  rare. 

Yoldia?  ValvulUB.     HALL  AND  WHITFIBLD. 

.Plate  IV.,  figures  4  and  5. 

Yoldia  ?  valvulus,  H.  and  W.    24th  Regent's  Rep.,  p.  190—1872. 
Yoldia  ?  valvulus,  H.  and  W.    27th  Regent's  Rep.,  pi.  11—1875. 

Shell  elongate,  narrow,  sub-elliptical,  more  than  twice  as  long  as  high,  the 
depth  a  little  more  than  half  the  height ;  anterior  end  nearly  one-fourth  wider 
than  the  posterior.  Beaks  situated  at  three-fifths  the  length  from  the  anterior 
end ;  an  obsolete  post-umbonal  ridge  extending  from  near  the  beak  to  the 
post-basal  margin  ;  posterior  extremity  not  recurved. 

Surface  marked  by  somewhat  coarse,  wavy,  concentric  lines  to  the  post- 
umbonal  ridge,  above  which  they  are  even  and  much  finer. 

i 

Formation  and  Locality. — Occurs  above  the  hydraulic  limestone  in  the  cherty  layers  of  the  De- 
vonian formation,  in  Jefferson  county,  Ky.,  and  in  Clark  county,  Ind.,  where  it  is  found  rather  abundantly 
in  silicified  specimens.  It  is  represented  by  fair  individuals  in  several  collections  in  the  Falls  Cities. 


Genus  Aviculopecten.    McCoy. 

Etymology:  resembling  the  shells  of  the  genus  Avicula. 
Aviculopecten  CraSSlcOStatllS.      HALL  AND  WHITF^ELD. 

• 

Aviciilopectfn  crassicasta/Ms,H.  and  W.     24th  and  27th  Reg.  Reps.,  p.  188,  and  pi.  11—1872  and  1875. 

Shell  below  medium  size,  its  body  broadly  ovate  or  sub-elliptical.  The  left 
valve  is  only  known  to  me,  and  shown  in  the  specimen  before  me ;  it  is  de- 
pressed convex  ;  body  of  the  shell  oblique  ;  hinge-line  straight,  equal  to  three- 
fourths  the  length  of  the  shell ;  anterior  wing  very  small,  separated  from  the 
body  of  the  shell  by  an  abrupt  deep  sinus;  posterior  wing  narrow,  obtusely 
pointed,  and  extending  nearly  as  far  as  the  posterior  extremity. 

Surface  marked  by  strong,  coarse,  angular  ribs,  of  which  there  are  about 


224  PALAEONTOLOGY    OF    KENTUCKY. 

» 

thirteen  or  fourteen  on  the  body  of  the  shell,  with  intermediate  smaller  ones ; 
about  five  obscure  rays  on  the  posterior  wing  ;  the  radiating  costae  crossed  by 
coarse,  distant,  lamellose,  concentric  ridges. 

Formation  and  Locality. — Found  in  the  hydraulic  limestone  of  the  Devonian  formation  at  the 
S*aih  of  the  Ohio,  in  Kentucky  and  Indiana,  where  it  is  a  rather  rare  shell. 

Aviculopecten  fasciculatus.     HALL. 

Plate  III.,  figure  4. 
Aviculopecten  fasciculatus,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  1,  page  11 — 1883. 

Shell  small,  obliquely  and  transversely  ovate  ;  height  about  equal  to  length, 
the  former  measuring  more  than  seven-eighths  of  the  latter.  Pallial  margins 
regularly  rounded,  becoming  more  convex  towards  the  middle  of  the  posterio 
lateral  margin,  and  extending  in  a  straight  or  slightly  concave  line  to  the 
beaks.  The  left  valve  is  only  known  to  me  ;  it  is  slightly  convex  in  its  basal 
half,  but  more  so  in  the  umbonal  region ;  the  umbo  is  prominent,  and  the  beak 
pointed  and  incurved.  The  hinge-line  is  straight  and  shorter  than  the  width 
or  length  of  the  shell ;  this  is  situated  anterior  to  the  middle  of  the  cardinal 
line.  The  anterior  ear  is  considerably  smaller  than  the  posterior  wing ;  both 
are  triangular  in  shape,  and  both  are  defined  by  a  sulcus,  of  which  the  posterior 
one  is  more  expressed  and  deeper.  The  posterior  wing  is  very  attenuate  at  the 
extremity.  Figure  4,  plate  3,  does  not  show  the  correct  shape  of  the  rear  wing; 
it  should  be  more  extended  in  the  hinge-line,  and  should  reach  downward 
only  half  as  far  as  it  does  in  that  figure.  The  terminal  margins  of  both  wings 
should  be  concave,  and  should  join  the  lateral  margins  of  the  shell  in  a  regular 
curve,  and  not,  as  represented  in  the  figure,  by  straight  lines. 

The  test  of  this  shell  is  ornamented  with  numerous  filiform,  radiating  striae, 
which  are  often  fasciculate,  and  by  fine  concentric  lines  of  growth.  In  young 
shells  the  radii  are  regular,  with  a  slight  fasciculate  arrangement.  The  concen- 
tric lines  are  sharper  and  more  crowded  on  the  wings,  while  the  radii  are  very 
much  subdued,  almost  obscure.  The  interior  of  this  shell  is  not  known, 
neither  have  I  ever  seen  its  right  valve. 

The  specimen  here  figured  and  described  measures  eight  lines  in  height, 
nine  lines  in  length,  and  its  hinge-line  is  five  lines  long.  This  species  has  some 
resemblance  with  A.  formio,  princeps  and  pecteniformis,  but  differs  from  them 
partly  by  its  form,  and  partly  by  its  surface-markings ;  from  A.  princeps 
mainly  by  the  presence  of  radii  on  its  wings. 

Formation  and  Locality, — Found  in  the  Corniferous  limestone  of  the  Devonian  formation  in 
Kentucky  and  Indiana,  at  and  around  the  Falls  of  the  Ohio. 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  225 

Aviculopecten  pecteniformis.    CONRAD. 

Plate  III.,  figure  1. 

Avicula  pecteniformis,  Conrad.     Jour.  Acad.  Nat.  Sci.  Phil. — 1842. 
Aviculopecten  pecteniformis,  Hall.     Pal.  of  N.  Y.,  Vol,  5,  pt.  1,  p.  4 — 1883. 

Shell  sub-ovate,  oblique  to  the  hinge-line ;  length  about  equal  to  height  ; 
anterior  and  basal  margins  regularly  rounded,  while  the  posterior  margin  of 
the  body  forms  an  almost  straight  line  to  beak.  Left  valve  almost  flat,  only 
moderately  convex  in  the  umbonal  region.  The  hinge-line  is  straight,  and  of 
about  two-thirds  the  length  of  shell,  or  even  somewhat  more.  Umbo  moder 
ately  elevated,  abruptly  sloping  to  the  wings,  thus  forming  a  demarcation-line 
between  the  ears  and  the  body  of  valve.  These  umbonal  lines  form  an  angle  of 
a  little  more  than  ninety  degrees.  The  wings  have  a  triangular  form  and  are 
of  medium  size,  the  anterior  one  having  but  little  more  than  half  the  area  of 
posterior  wing.  The  beak  is  of  moderate  size  and  pointed  ;  it  is  located  ante- 
rior to  the  middle  of  the  cardinal  line.  The  terminal  margins  of  the  wings 
are  more  or  less  concave.  The  interior  of  this  shell  and  its  right  valve  are  not 
known. 

Test  is  thin  and  ornamented  by  about  thirty-five  sharp  and  strong  radiating 
striae,  with  intermediate  finer  ones,  which  are  crossed  by  fine,  imbricating, 
concentric  lines  of  growth,  some  of  which  are  more  prominent,  and  divide  the 
surface  in  different  concentric  zones. 

On  the  wings  the  radiating  striae  are  obsolete,  and  even  the  lines  of  growth 
are  there  scarcely  visible.  This  species  is  variable  in  its  dimensions  in  differ- 
ent specimens.  The  one  before  me  measures  twenty-five  lines  in  height,  by 
two  inches  in  length,  and  with  a  hinge-line  of  one  inch  and  one-half. 

This  species  has  great  resemblance  to  A.  princeps,  from  which  it  differs, 
however,  by  its  smaller  ears,  and  by  its  coarser  or  stronger  principal  radii, 
while  the  intermediate  finer  striae  are  so  fine  as  being  scarcely  visible  to  the 
naked  eye,  which  makes  the  interspaces  between  the  principal  striae  appear  to 
have  three  times  the  width  of  these  radii. 

Formation  and  Locality. — Occurs  in  the  Corniferous  limestone  of  the  Devonian  formation  at  and 
around  the  Falls  of  the  Ohio,  in  Kentucky  and  Indiana.  It  is  a  rather  rare  species,  especially  in  fair  or 
well  preserved  specimens.  • 

Aviculopecten  princeps.    CONBAD. 

Monotis  jtrinceps,  Conrad.     Ann.  Kep.  N.  Y.  Geol.  Surv. — 1838. 
Avicula  parilis,  Conrad.     Proc.  Acad.  Nat.  Sci.  Phil.,  Vol.  8—1842. 
Aviculopecten  princeps,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  1 — 1883. 
Aviculopecten  sanduskyensis,  Hall.   Pal.  N.  Y.,  Vol.  5,  pt.  1 — 1883. 

Shell  large,  obliquely  broad-ovate ;  axis  inclined  more  than  sixty  degrees  to 
the  hinge-line  ;  length  and  height  nearly  equal,  varying  within  moderate 

GEOL.   SUK. — 29 


226  PALAEONTOLOGY    OF    KENTUCKY. 

limits.  Anterior  margin  convex,  the  convexity  increasing  to  the  middle  of 
the  postero-lateral  side,  thence  truncated  and  extending  in  a  straight  line  to 
the  beak,  making  an  angle  of  from  thirty  to  forty  degrees  with  the  hinge- 
line. 

Valves  depressed ;  left  valve  regularly  convex ;  right  valve  nearly  flat  or 
only  slightly  convex.  The  hinge- line  is  straight,  having  a  length  of  from 
two-thirds  to  more  than  three-fourths  the  length  of  the  shell,  and  extending 
anteriorly  as  far  as  the  anterior  margin.  The  beaks  are  obtuse,  rounded  and 
anterior  to  the  middle  of  the  hinge-line.  Umbo  of  left  valve  is  little  convex, 
somewhat  inflated,  and  the  lines  of  demarcation  between  it  and  the  anterior 
and  posterior  wings  form  an  angle  of  about  one  hundred  and  thirty  degrees. 
The  wings  comparatively  only  of  medium  extent ;  the  anterior  considerably 
smaller  than  the  other ;  both  are  triangular  in  shape.  The  anterior  ear  is  sepa- 
rated from  the  body  by  a  distinct  sulcus,  while  the  posterior  wing  is  defined  by 
the  abrupt  slope  of  the  posterior  side  of  the  umbo.  This  slope  is  formed  by 
an  almost  rectangular  deflection  of  the  posterior  margin,  and  has  a  height  of 
about  one  line.  The  terminal  margins  of  the  beaks  are  more  or  less  concave, 
becoming  convex  at  the  hinge-line.  Byssal  sinus  broad,  rounded,  well  defined, 
and  indicated  on  the  ear  by  a  sulcus  extending  to  the  extremity  of  the  beak. 

Test  is  thin,  marked  by  numerous  regular  alternating  rays  or  radii,  which 
increase  in  number  by  interstitial  additions,  and  become  broader  and  stronger 
towards  the  margins.  These  radii  are  crossed  by  very  fine,  sharp  lines  of 
growth.  On  the  wings  the  radiating  striae  are  obsolete,  while  the  lines  of 
growth  are  there  sharper  and  stronger  than  on  the  body  of  the  shell. 

The  dimensions  of  the  shells  in  this  species  are  very  variable  ;  there  are  very 
large  and  also  very  small  specimens.  The  one  before  me,  which  is  one  of  the 
largest  ever  found,  measures  thirty  lines  in  height,  thirty- two  lines  in  length, 
and  has  a  hinge-line  twenty-seven  lines  long ;  here  the  length  exceeds  the 
height,  and  the  hinge-line  is  shorter  than  height  or  length  ;  but  we  find  speci- 
mens belonging  to  this  species  where  all  three  dimensions  are  nearly  equal. 

This  species  resembles  A.  pecteniforniis,  but  differs  from  it  by  its  larger 
wings  and  by  its  more  numerous  and  less  prominent  radii.  This  is  one  of  the 
largest  shells  of  the  genus  Aviculopecten,  and  is  easily  identified  by  its  form 
and  surface-markings.  All  the  forms  heretofore  placed  In  the  two  species  of 
A.  sanduskyensis  and  A.  parilis,  belong  to  the  present  one.  The  apparent  spe- 
cific differences  noted  in  the  description  of  these  three  forms  are  neither  con- 
stant nor  well  defined,  and  not  even  sufficient  to  base  upon  them  a  separation 
into  different  varieties. 

Formation  and  Locality. — This  species  occurs  in  the  Corniferous  limestone  at  and  around  the  Fall* 
of  the  Ohio,  in  Kentucky  and  Indiana,  where  fair  specimens  are  not  very  rare,  though  not  abundant 
either, 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  227 

Genus  Glyptodesma.    Han. 

Glyptodesma,  Hall.     N.  T.  Rep.,  Vol.  6,  pt.  1. 
Etymology:  glyptos,  curved;  desm-a,  a  ligament. 

Shell  aviculoid,  erect  or  moderately  oblique  ;  inequivalve.  Ligament  exter- 
nal. Ligamental  area  striated,  continuous.  Hinge  with  two  strong,  lateral 
teeth,  and  numerous  irregular  transverse  plications  along  the  cardinal  margin. 
In  form  the  shells  of  this  genus  resemble  Actinodesma,  but  they  have  not  the 
permanent  diverging  teeth  of  that  genus.  Surface  marked  by  concentric 
striae. 

Glyptodesma  cancellata.    N.  SP. 

Plate  V.,  figure  1. 

Shell  large,  regularly  oviform  in  its  body,  almost  erect  or  slightly  oblique  ; 
height  exceeding  length ;  anterior  and  posterior  margins  broadly  rounded ; 
front  or  base  strongly  curved  ;  posterior  wing  large  ;  its  posterior  margin  con- 
cave, and  its  extremity  produced  to  a  salient  point ;  anterior  wing  defective 
in  the  specimen  before  me,  but  it  appears  to  be  short,  and  of  the  shape  as 
indicated  in  figure  1,  plate  5.  The  hinge-line  is  about  equal  in  size  to  width 
of  the  shell.  Only  the  left  valve  is  known  ;  it  is  very  convex  and  gibbous  in 
the  umbonal  region,  from  where  it  slopes  in  a  gentle  curve  to  the  margins  in 
the  basal  half  of  the  valve.  The  lateral  slopes  of  the  umbonal  region  are 
abrupt,  the  anterior  somewhat  more  than  the  posterior.  There  is  no  sharp 
dividing  line  between  the  body  and  wings.  The  posterior  wing  is  very  convex, 
sloping  rapidly  or  even  abruptly  to  the  cardinal  line,  which  is  entirely  straight. 
The  interior  of  this  shell  and  its  right  wing  are  unknown.  The  umbo  is  promi- 
nent, and  the  beak  elevated  and  incurved  over  the  hinge- line ;  it  is  located 
anterior  to  the  middle  of  the  shell,  and  has  an  anterior  direction.  The  surface 
is  marked  by  strong,  simple,  rounded,  radiating  plications,  with  wide,  flat 
interspaces,  which  are  about  three  times  as  wide  as  the  ribs.  There  is  scarcely 
an  intercalated  plication  observed  on  the  whole  valve ;  no  bifurcation  takes 
place. 

The  specimen  here  described  and  figured  is  well  preserved,  with  the  ex- 
ception of  the  anterior  wing,  which  is  either  broken  or  covered  with  rock;  this 
shell  measures  thirty-one  lines  in  height,  by  twenty-nine  lines  in  length.  The 
surface  is  divided  by  several  strong  lines  of  growth  into  concentric  zones. 

Formation  and  Locality. — Found  in  the  Corniferous  limestone  of  the  Devonian  formation  at  and 
around  the  Falls  of  the  Ohio,  in  Kentucky  and  Indiana.  The  specimen  illustrated  on  plate  5  is,  so  far,  the 
only  one  known. 


228  PALEONTOLOGY    OF    KENTUCKY. 

Glyptodesma  occidentale.    HALL. 

Plate  III.,  figure  5. 
Glyptodesma  occidentale,  Hall.     Pal.  N.  Y.,  Vol.  5,  part  1,  page  157—1884. 

Shell  large,  broadly  ovate  ;  body  nearly  erect ;  height  somewhat  greater  than 
the  length.  The  specimen  before  me  measures  thirty-eight  lines  in  height  by 
thirty-four  lines  in  length.  All  the  margins  are  regularly  curved,  with  about 
the  same  radius. 

Of  the  two  valves  of  the  shell,  only  the  left  one  is  known ;  it  is  somewhat 
gibbous  at  the  umbo,  from  where  it  slopes  in  a  gentle  curve  down  to  the  base 
and  to  the  basal  half  of  the  anterior  and  posterior  margins  ;  in  the  upper  half 
of  the  valve  the  lateral  slopes  of  the  umbonal  region  are  abrupt,  more  so  on 
the  anterior  than  on  the  posterior  side.  The  hinge-line  is  straight  and  con- 
siderably shorter  than  the  width  of  the  shell ;  in  our  specimen  it  measures 
about  two- thirds  of  the  greatest  width  of  shell.  Prof.  Hall's  figure,  on  plate 
86,  of  volume  5,  part  1,  shows  an  enormously  extended  wing,  and  consequently 
a  very  large  hinge-line,  but  it  appears  to  me,  that  in  restoring  the  wing,  which 
in  Prof.  Hall's  specimen  was  missing  to  the  extent  of  an  inch  and  one-quarte 
on  the  posterior  margin,  a  considerable  mistake  was  made  in  regard  to  its 
length,  although  the  concentric  lines,  near  the  edge  of  the  broken  wing,  indi- 
cated a  very  mucronate  one.  My  specimen  is  almost  perfect  and  shows  a  wing 
as  illustrated  in  figure  5,  plate  3.  The  beak  is  anterior  to  the  middle  of  the 
shell,  with  a  strong  inclination  to  the  anterior  end ;  it  is  prominent  and  acute. 
The  anterior  wing  is  short,  defined  by  a  deep  sulcus,  and  marked  byssal  in- 
flection or  sinus  just  anterior  to  the  beak.  Posterior  wing  is  large,  depressed, 
convex,  moderately  extended,  joining  the  body  of  the  shell  at  the  middle,  and 
defined  partly  by  the  recurving  of  the  striae,  but  more  decidedly  by  a  small 
but  plainly  visible  depression,  which  extends  in  a  straight  line  from  the  cardi- 
nal line  near  the  beak  along  body  of  the  valve  to  the  posterior  margin  at  the 
middle  of  the  shell.  The  posterior  margin  of  the  wing  is  slightly  concave, 
and  its  extremity  somewhat  produced,  but  not  to  such  an  extent  as  shown  in 
Prof.  Hall's  figure. 

Test  thick,  marked  by  numerous  fine  striae  or  lines  of  growth,  which  at  inter- 
vals are  crowded  into  fascicles,  producing  an  undulating  surface.  These  striae 
are  more  closely  arranged,  and  become  lamellose  on  the  anterior  part  of  shell. 
On  the  posterior  wing  the  striae  are  regular,  and  at  distant  intervals  a  single 
stria  becomes  sharply  elevated.  The  interior  of  this  shell  and  its  right  valve 
are  unknown. 

This  species  resembles  G-.  erectum,  but  appears  to  be  a  more  robust  form ; 
the  shell  is  more  orbicular,  the  umbonal  region  more  gibbous,  the  surface  more 
rugose  from  the  undulations  of  the  fascicles  of  striae,  and  the  limitation  be- 


FOSSILS    OF    THE    SILURIAN    AND    DEVONIAN    ROCKS.  229 

tween  the  body  and  the  posterior  wing  is  less  strongly  defined.  These  are  the 
differences  marked  out  by  Prof.  Hall.  It  appears  to  me  that  in  all  these  points 
shells  may  differ  and  still  belong  to  the  same  species,  and  especially  in  this 
case,  where  the  most  important  distinction,  the  last  mentioned  one,  disappears, 
inasmuch  as  Prof.  Hall  did  not  notice  in  his  specimen  the  dividing  sulcus  be- 
tween body  and  posterior  wing,  which  my  shell  so  plainly  shows. 

Formation  and  Locality. — Found  in  the  Corniferous  limestone  at  and  around  the  Falls  of  the  Ohio, 
in  Kentucky  and  Indiana. 


Genus  Actinopteria. 

This  genus  is  established  by  Prof.  Hall  in  his  N.  Y.  Rep.,  Vol.  5,  part  1, 
Lamellibranchiata.  His  description  is : 

Characterized  from  Pterinea  in  the  absence  of  a  broad  striated  ligamental 
area  and  strong  cardinal  teeth.  Eight  valve  sub-convex.  Surface  with  tine 
rays. 

Actinopteria  boydi.    CONRAD. 

Plate  III.,  figure  2. 

Avicula  boydi ,  Conrad.    Jour.  Acad.  Nat.  Sci.  Phil. — 1842. 
Avicula  quadrula,  Conrad.    Jour.  Acad.  Nat.  Sci.  Phil. — 1842. 
Actinopteria  boydi,  Hall.     Pal.  N.  Y.,  Vol.  5,  pt.  1,  p.  113—1883. 

Shell  of  medium  size,  rhomboidal ;  body  ovate,  varying  in  the  proportion 
of  its  dimensions.  Its  longitudinal  axis  forms  with  the  hinge-line  an  angle 
of  from  forty-five  to  sixty  degrees.  Length  and  height  sometimes  nearly 
equal,  but  in  some  specimens  the  length  is  one-fourth  greater  than  height. 
The  margins  in  the  basal  half  of  the  shell  regularly  rounded;  in  the  upper 
half  of  the  valve  anterior  margin  of  the  body  is  almost  straight  or  very  little 
curved,  while  the  posterior  border  of  the  body  is  entirely  straight  or  even 
slightly  concave.  The  post-basal  part  of  the  shell  is  extended.  The  left  valve, 
which  is  only  preserved  in  the  specimen  before  me,  is  moderately  convex 
throughout  the  whole  body.  The  umbo  is  somewhat  more  elevated;  its  ante- 
rior slope  is  gentle,  while  the  posterior  descent  is  abrupt,  meeting  surface  of 
the  posterior  wing  almost  at  right-angles,  thus  forming  a  sulcus  by  which 
the  rear  wing  is  defined. 

The  hinge-line  is  straight  from  the  anterior  side  of  beak  to  the  posterior  ex- 
tremity. Beak  anterior,  acute,  prominent,  inclined  forward,  and  rising  above 
the  cardinal  'line ;  the  umbonal  margins  form  an  acute  angle  of  less  than 
sixty  degrees.  Front  ear  short,  oblique,  limited  by  a  deep,  but  not  sharply 


'230  PALEONTOLOGY    OF    KENTUCKY. 

defined  sulcus.     Terminal  margin  of  the  rear  wing  concave,  and  the  cardinal 
extremity  acute. 

The  test  is  thick ;  the  left  valve,  in  well  preserved  specimens,  is  covered  by 
numerous  strong,  simple,  sharp,  radiating  striae,  which  are  continuous  from 
the  umbo  to  the  margin ;  intercalated  radii  are  very  seldom,  but  when  they 
exist  they  are  finer  than  the  balance.  The  radii  are  crossed  by  regular, 
sharp,  elevated,  concentric  lamellae,  which,  in  well  preserved  specimens,  are 
produced  into  sub-tubular,  spiniform  extensions  upon  the  rays.  On  the  wings 
the  radii  are  less  conspicuous,  while  the  concentric  lines  of  growth  are  there 
more  prominent  and  crowded.  The  specimen  here  described  and  figured  meas- 
ures in  both  height  and  length  fifteen  lines,  and  its  hinge-line  thirteen  lines. 

Formation  and  Locality. — Occurs  in  the  Corniferous  limestone  of  the  Devonian  formation  at  and 
around  the  Falls  of  the  Ohio. 


INDEX  TO  GENERA  AND  SPECIES  DESCRIBED. 


PROTISTA. 

PLATES. 

Brachiospongia 

digitata 35,  36 

BRYOZOA. 
Ptilodictya 

hilli 35 

BRACHIOPODA, 
Ambocoelia 

umbonata  __ 17 

.  .nastrophia 

internascens 32 

Athyris 

vittata. --- - 16 

Atrypa 

aspera 14 

calvini -  - - 32 

ellipsoida - 

reticularis. - 14,  15 

reticularis,  var.  niagarensis 32 

Camarella 

congesta - - - 

Centronella 

glans-fagea -  31 

Ghonetes 

acutiradiata  18 

subquadrata - - -- 

yandelliana 17,  31 

Crania 

bordeni    --- , ..-          2 


232  INDEX. 

PLATES. 

Cyrtia 

exporrecta 27 

exporrecta,  var.  arrecta 27,  32,  34 

Cyrtina 

crassa__ 13 

hamiltoniae 13 

hamiltoniae,  var.  recta 13 

Discina 

doria 

grandis '.. , 3 

Leiorhynchus 

quadricostatus 


Leptocoelia 

hemispherica   1 32 

Lingula 

triangulata  - 31 

Meristella 

nasuta _..  15 

unisulcata 15 

Meristina 

maria : 29 

nitida %-  -  - - 33 

Nucleospira 

concinna . 32 

elegans .- - 

pisif ormis  33 

Orthis 

bif orata 29 

borealis 34 

elegantula 32 

flabellum  34 

goodwini   17 

hybrida 32 

livia 16,  17 

linneyi r 34 


INDEX.  233 

PLATKS. 

Orthis — Continued. 

nisis 27 

propinqua 16 

rugaeplicata  27 

subnodosa 

vanuxemi ._ 16 

Fentamerella 

arata 13 

papilionensis 

thusnelda 31 

Pentamerus 

complanatus 27 

globulosus _ . 

knappi 28 

knotti 32 

knighti 29 

littoni 27 

nucleus 27,  33 

nysius,  var.  crassicostus 28 

nysius,  var.  tenuicostus 

oblongus    33 

oblongus,  var.  cylindricus _  _ 30 

pergibbosus 29 

uniplicatus  33 

ventricosus   _ 33 

Productella 

semiglobosa 26 

subaculeata,  var.  cataracta 17 

Rhynchonella 

acinus — -  -  - 32,  26 

bellaf  orma  1 . 

Carolina . -.   - 13 

gainesi   -  -  - 31 

increbescens 34 

indianensis 33 

louisvillensis . . 31 

pisa 32 

rugaecosta 32 

saffordi - ._._-..,._.  _.Tr ._,,_._,____  27,  33 

.    SUK. — 30 


234  INDEX. 

PLATES. 
Rhynchonella— Continued. 

saft'ordi,  var.  depressa 33 

Strickland! 29,  27 

tenuistriata 17 

tethys - 13,  31 

Rhynchotreta 

cuneata,  var.  americana    32 

Spirifera 

acuminata 8 

arctisegmenta '. . .  12 

atwaterana 9 

byrnesi 10 

conradana .... 7 

crispa,  var.  simplex  17 

davisi   12 

divaricata  11,  12 

dubia _ 33 

duodenaria 12 

euruteines  6 

euruteines,  var.  f ornacula 6 

foggi 32 

gregaria 8,  10 

grieri 9 

hobbsi ...  10 

knappiana    7 

macconathii  .  _ 11 

marionensis • 

medialis 26 

mucronata 31 

oweni ._  7 

radiata 29 

raricosta 17 

rostellum 27,  29 

sculptilis  31 

segmenta .  . . 13 

varicosa , 10 

Streptorhynchus 

arctostriata 31 

subplanus 29 

tenuis  . 


INDEX.  235 

PLATES. 

Stricklandinia 

louisvillensis 34 

Strophodonta 

demissa 33,  18 

hemispherica   18 

inequistriata 17 

nacrea 

perplana 18 

plicata 

prof unda 17,  29 

striata   

Strophomena 

rhomboidalis  (Devonian) 18 

rhomboidalis  (Silurian) 

Terebratula 

harmonia - 17 

jucunda 

lincklaeni 17 

roemingeri _ .  - ..- 16 

Trematospira 

hirsuta  16 

helena 32 

Tropidoleptus 

carinatus  - -- 17 

Zygospira 

kentuckiensis - 34 

PTEROPODA. 
Styliola 

fissurella   

Tentaculites 

sialariformis 31 

GASTEROPODA. 
Bellerophon 

leda  .  --- 17 


236  INDEX. 

PLATES. 

Bucania 

devonica _ - 26 

Gallonema 

bellatula -- 20 

clarki 24 

imitator 20 

Cyclonema 

cancellata - 20 

multilira — 22 

rugaelineata 33 

Euomphalus 

deceini — 21 

sampsoni --- 21 

Loxonema 

hamiltoniae 31 

hydraulicum 20 

laeviusculum 22 

rectistriatum - 

Macrocheilus 

carinatus - - - 20 

Murchisonii 

desiderata 26 

petila _        31 

Platyceras 

bucculentum    23 

compressum   25 

conicum 25 

dumosum . - 23 

dumosum,  var.  rarispinum 23 

echinatum -- 31 

erectum - .-. 

milleri 25 

nmltispinosum 25 

rictum - - 

symmetricum 23 

thetis - 

unguif  orme 

ventricosum  25 


INDEX.  237 

PLATBS. 

Platyostoma 

lineata 19,  21 

lineata,  var.  callosa 21,  22,  25 

niagarense 33 

turbinata _ 21 

turbinata,  var.  cochleata 

Pleurotomaria 

arabella . 26 

casii 26 

lucina 

procteri 21 

sulcomarginata 21 

Polyphemopsis 

louisvillae. 20 

Strophostylus 

varians — 22 

Trochonema 

f atua 

rectilatera 20 

yandellana 20 

Turbo 

shumardi 19,  22 


CEPHALOPODA. 

Gomphoceras 

oviforme - 21 

turbinif orme  21 

Goniatites 

discoideus -  — --        20 

Lituites 

marshi --- 30 

Nautilus 

maximus. . 24 


238  INDEX. 

LAMELLIBRANCHIATA. 

PLATES. 

Actinopteria 

boydi 3 

Aviculopecten 

crassicostatus 

f asciculatus 3 

pecteniformis  3 

princeps 

Clinopistha 

antiqua 

striata 4 

subnasuta   4 

Conocardium 

cuneus  5 

Cypricardinia 

cataracta  4 

cylindrica 4 

inflata,  var.  sub-equivalvis 

Cypricardites 

halli   . 34 

Glyptodesma 

cancellata . 5 

occidentals 3 

Goniophora 

truncata 4 

Grammysia 

gibbosa _ „ 4 

Limoptera 

cancellata 3,  4 

Modiomorpha 

affinis 

alta 26 

charlestownensis 5 

concentrica 2 

mytiloides 


INDEX.  239 

PLATES. 

Nucula 

herzeri   _. 

neda 5 

niotica 5 

Paracyclas 

elliptica 2 

elongata _ 2 

lirata 2 

octerlonii 31 

ohioensis  .  - 6 

Ptychodesma 

knappianum - 2 

Yoldia 

valvulus - 4 


PROTISTA. 

FAGB. 

Brachiospongia  digitata -  -  - - 29 

BRYOZOA 

Ptilodictya  Mill 30 

BRACHIOPODA. 

X 

Ambocoelia  nmbonata 86 

Anastrophia  internascens 47 

Athyris  vittata 87 

Atrypa  aspera 88 

calvini  __ ...  89 

ellipsoida 90 

reticularis 91 

reticularis,  var.  niagarensis 92 

Camarella  congesta 48 

Centronella  glans-fagea . 153 

Chonetes  acutiradiata 66 

snbquadrata . .-_  67 

yandelliana - 68 

Crania  bordeni 32 

Cyrtia  exporrecta - 93 

exporrecta,  var.  arrecta 94 

Cyrtina  crassa - 95 

hamiltoniae 96 

hamiltoniae,  var.  recta 97 

Discina  doria 32 

grandis 33 

Leiorhynchus  quadricostatus _  _  _  _  r ...  r ......... , , .  r ,  r . , . , ,  _ .....  r =  71 


INDEX.  241 

PAGE. 

Leptocoelia  hemispherica  _  _ _• 152 

Lingula  triangulata 34 

Meristella  nasuta 98 

unisulcata 99 

Meristina  maria 101 

nitida. 102 

Nucleospira  concinna  103 

elegans 104 

pisiformis ]  04 

Orthis  biforata , _  _  _  35 

borealis 36 

elegantula 37 

flabellum  38 

goodwini  _ _ 39 

hybrida 39 

livia , 40 

linneyi 41 

nisis 42 

propinqua 43 

rugaeplicata 44 

subnodosa 44 

vanuxemi „ , 45 

Pentamerella  arata , .  49 

papilionensis ... 50 

thusnelda 61 

Pentamerus  complanatus 63 

globulosus  64 

knappi -  55 

knighti _• 67 

knotti - 66 

littoni ,.__- . 58 

nucleus 69 

nysius,  var.  crassicostus 60 

nysius,  var.  tenuicostus 60 

oblongus  60 

oblongus,  var.  cylindricus 61 

pergibbosus : 62 

uniplicatus  63 

ventricosus 64 

Prgductella  semiglobosa  ............ , . , ,  T , . .. . 7Q 

GKOL.   SUK. — 31 


242  INDEX. 

PAGE 

Productella  subaculeata,  var.  cataracta 69 

Rhynchonella  acinus 73 

bellaf  orma 73 

Carolina.  _ _. 75 

gainesi  76 

increbescens 83 

indianensis   76 

louisvillensis 77 

pisa 78 

rugaecosta 78 

saffordi 79 

saffordi,  var.  depressa 80 

stricklandi 81 

tenuistriata  _ 82 

tethys : 83 

Rhynchotreta  cuneata,  var.  americana    85 

Spirif era  acuminata 105 

arctisegmenta 108 

atwaterana   107 

byrnesi 109 

conradana 110 

crispa,  var.  simplex  111 

davisi , 112 

divaricata 113 

dubia .__ 115 

dnodenaria  114 

euruteines 115 

eurnteines,  var.  fornacula 117 

foggi _ 117 

gregaria 119 

grieri _  120 

hobbsi    121 

knappiana 122 

macconathii 123 

marionensis . .  _ 124 

medialis.. 125 

mucronata 126 

oweni 126 

radiata  .  _ 130 

raricosta    ,. .,.„„.  123 


INDEX.  243 

PAGE. 

Spirifera  rostellum " 129 

sculptilis  132 

segmenta 132 

varicosa 134 

Streptorhynchus  arctostriata 140 

subplanus 141 

tenuis .  _ . .  142 

Stricklandinia  louisvillensis 65 

Strophodonta  demissa 143 

hemispherica  144 

inequistriata 145 

nacrea .., 146 

perplana  147 

plicata 149 

profunda . 148 

striata 149 

Strophomena  rhoraboidalis  (Devonian) 150 

rhomboidalis  (Silurian)  151 

Terebratula  harmonia 154 

jucunda. 154 

lincklaeni 155 

roemigeri - -  155 

Trematospira  hirsuta 136 

helena  137 

Tropidoleptus  carinatus —  46 

Zygospira  kentuckiensis .  138 


PTEROPODA, 

Styliola  fi  ssurella    - 157 

Tentaculites  scaliformis   .  156 


GASTEROPODA. 

Bellerophon  leda -- 158 

Bucania  devonica    . 160 

Callonema  bellatula 175 

clarki   - 175 

imitator  .  176 


244  INDEX. 


Cyclonema  cancellata    .....................  _______  .....  ...  ..........  .  .  187 

multilira  ____  ............  ...  .....  ____________  .........  ___________  188 

rugaelineata  ........  _________________  ____  .......  ________________  187 

Euomphalus  decewi  _____________________________  .....  _________________  181 

sampsoni  ________________________  .....  .  .  ...........  ______  ......  182 

Loxonema  hamiltoniae  ____  ......  _____________  .................  ________  177 

hydraulicum  ..........  _____  .....  .  ____________  ........  ________  ._  178 

laeviusculum   _________________________  ..........  ________  .....  ..  178 

rectistriatum    ________________  .  .................  _____  .........  ..  179 

Macrocheilus  carinatus  .....  ________  .......   ........  ___________   _______  180 

Murchisonia  desiderata  ______  .....  _________  ..........  ____  ...........  _  .  169 

petila  ...........  ____________  .....  _____________  .....  _____________  170 

Platyceras  bucculentum  .  .  ......  ._  .......  _______________  ..............  160 

compressum  .........  __________________  .......  __________________  162 

conicum  ____________________________________  ......  _____________  161 

dumosum  ................  ___________  ........  __________  ......  .  _  _  162 

dumosum,  var.  rarispinum  _________________  .......  _______________  163 

echinatum    ........  .......  ___  .....  .  .....  _  _  .......  ______________  164 

erectum  ......  __________  .........  ___________________________  .....  165 

milleri   ........  ___________  ........  .  .....  _______________________  166 

multispinosum  ......  ______  .....  _________________________  .....  .  .  166 

rictum  .  .....  _____________  ________________________________  ......  166 

symmetricum  ...  .....  __________________________________________  167 

thetis  ..............  _____________________________________________  1  68 

unguiforme  _______________________________________________________  168 

ventricosum   __________  _______________________  ........  ___________  168 

Platyostoma  lineata  ________________     .   ...  ......  ______________________  183 

lineata,  var.  callosa  _____________________________________________  184 

niagarense  ____________________  .....  ____________________  '  ______  .  ____  185 

turbinata  _________________  _____________________________________  184 

turbinata,  var  cochleata  ______________________  .....  ______________  185 

Pleurotomaria  arabella  ...........  _  .....  _____  .....  _____________________  171 

casii    _______  ......  .  .  ......  _____________________________________  171 

lucina.  ............  ____________  .....  _______   ..   ____  .  _____________  172 

procteri  ____  ........  _  ..........  ..  .....  __________________________  173 

suJcomarginata    _____________________  .......  ____________________  174 

Polyphemopsis  louisvillae  _______  ........  _______________________________  180 

Strophostylus  varians  ________________________________________________  186 

Trochonema  f  atua  ......  ..........  ________________________________  ____  189 

rectilatera  ........  _______________  ......  .  .  ......  __________________  189 

yandellana    ..........  __________________________________________  190 

Turbo  shumardi  .  191 


INDEX.  245 
CEPHALOPODA. 

PAGE 

Gomphoceras  oviforme _ 103 

turbinif orme    _. 194 

Goniatites  discoideus _ 194 

Lituites  marshi __ 195 

Nautilus  maximus 196 

LAMELLIBRNACHIATA. 

Actinopteria  boydi _ 229 

Aviculopecten  crassicostatus 223 

f  asciculatus _ 224 

pecteniformis.  __ 225 

princeps 225 

Clinopistha  antiqua  200 

striata 200 

subnasuta   _. 199 

Conocardium  cuneus 203 

Cypricardinia  cataracta 204 

cylindrica ._ 205 

inflata,  var.  sub-equivalvis 206 

Cypricardites  halli 206 

Glyptodesma  cancellata 227 

occidentale  -..  228 

Goniophora  truncata    214 

Grammysia  gibbosa  ._ 208 

Limoptera  cancellata -  - 198 

Modiomorpha  affinis 216 

alta 217 

charlestownensis.  _ 218 

concentrica  219 

mytiloides 220 

Nucula  herzeri _  _  _ , 221 

neda 222 

niotica ' - 222 

Paracyclas  elliptica   209 

elongata -  -  - 210 

lirata    211 

octerlonii : 212 

ohioensis 213 

Ptychodesma  knappianum 201 

Yoldia  valvulus  .  223 


PAUGQNTQLOCR  OF  KENTUCKY. 


77> 


H  rp-p     T 
lA  i  JTj    A 


OEl.  AMO  LITH.  BV  TOM    TULEV. 


LOUISVILLE    LITH.  CO. 


PLATE  L 

CEPHALOPODA. 
Belemnitella  mucronata. 

Fig.  16.  View  of  the  internal  shell.  Page  22 

Sepia  officiiialis.     LINNE. 

Fig.  12.  View  of  a  specimen.  Page  22 

a.  Arms. 

b.  Tentacles. 

c.  Eyes. 

Nautilus  pompilius. 

Fig.  24.  View  of  the  animal  and  shell,  the  latter  sawed  through 

the  middle.  Page  22 

a  a.  Air  chambers. 
b  b.  Septa. 
c  c.  Siphuncle. 


Goniatites  henslowi. 
Fig.  18.  View  of  a  specimen,  the  outer  shell  entirely  removed.  Page  22 

CeratitCS   IlOdoSUS.      BRUGUIKRK. 

Fig.  19.  View  of  a  specimen,  outer  shell  entirely  removed.  Page  22 


TurrilitCS  COStatllS.      LAMABK. 

Fig.  2.  Apertural  view  of  a  specimen.  Pages  22  and  23 

a.  Apex. 
a  f .  Spire. 

b.  ( 

c.  <  Sutures. 

d.  ( 

g.  Aperture, 


Bacilli tes  ancepS-      LAMAKK. 

Fig.  1.  View  of  the  internal  shell.  Page  22 

a.  Aperture. 

b.  Septa. 

c.  Sutures. 


PLATE  I. 


GASTEROPODA. 


Triton  COlTUgatuS.      LAMARK. 

Fig.  23.  Longitudinal  section  of   a  specimen.     The  upper  part  of  the 

spire  has  been  partitioned  on0  many  times  successively.  Page  23 


Fascioloria  tulipa. 


Fig.  14.  Apertural  view  of  a  specimen.     Dextral.  Page  23 

a.  Posterior  canal. 

b.  Anterior  canal. 
d.  Labrum. 


FUSUS  antiquus.     MUELLER. 

Fig.  15.  Apertural  view  of  a  specimen.     Sinistral.  Page  23 

a.  Posterior  canal. 

b.  Anterior  canal, 
f.  Labrum. 


Faludina  listen.    HANLEY- 

Fig.  21.  Apertural  view  of  a  specimen.     Dextral.  Page  23 

a.  Aperture,  closed  by  operculum. 

b.  apex. 


Ampullaria  bolteniana.    CHEMNITZ. 
Fig.  10.  Apertural  view  of  a  specimen.     Sinistral.  Page  2 


Chiton  squamosus. 
Fig.  11.  Dorsal  view  of  a  specimen.  Page  22 

Helix  desertorum.    FOSSKAL. 
Fig.  13.  View  showing  animal  and  manner  of  bearing  shell.  Page  22. 

PLATE  I. 

PTEROPODA. 

Hyalaea  tridentata.    LAMARK. 
Fig.  4.  Dorsal  view  of  a  specimen.  Page  23 

Conularia  trentonensis.    HALL. 
Fig.  5.  Front  view  of  a  specimen.  Page  23 


BRACHIOPODA. 
Terebratula  dorsata.    SMKLTN. 

Pig.  26.  View  of  a  dorsal  valve.  Page  24 

a.  Crura  of  the  loop. 

b.  Loop. 

c.  Septum. 

Fig.  22.  Magnified  section  of  shell  of  Terebratula.  Page  24 


Waldheimia  australis.    KINO. 

Fig.  6.  View  of  dorsal  valve.  Page  24 

b.  Loop. 

1.  Reflected  portion  of  loop, 
m.  Abductor, 
p.  Hinge  plate. 
s.  Septum. 


Waldheimia  australis.    KING. 

Fig.  25.  View  of  ventral  valve.  Pages  23  and  24 

a.  Single  abductor  impression. 

b.  Foramen. 

c.  Deltidium. 

d.  Teeth. 

r.  Cardinal  muscles. 

v.  Portion  of  the  vent. 

z.  Attachment  of  pedicle  sheath. 


Spirifera  striata. 

Fig.  7.  View  of  dorsal  valve  showing  spiral  cones.  Page  24 


Athyris  concentrica. 

Fig.  8.  View  of  dorsal  valve  showing  spiral  cones.  Page  24 


Rhynchonella  ptissacea. 
Fig.  9.  View  of  dorsal  valve,  showing  spiral  arm  unrolled.  Page  24 

PLATE  I. 

LAMELLIBRANCHIATA. 

Modiola  lithophaga.     LINNE. 

Fig.  17.  View  of  right  and  left  valve.  Page  25 

a.  Dorsal  margin. 

b.  Anterior  margin. 

c.  Posterior  margin. 

d.  Posterior  margin. 

Cytherea  chione.     LINNK. 

Fig.  3.  View  of  left  valve.  Page  25 

a  Anterior  abductor. 
a.  Posterior  abductor. 

e.  Cardinal  tooth. 
d.  Umbo. 

h.  Hinge  linament. 

f.  Lunule. 

p.  Pallial  impression. 
t\  Lateral  teeth. 
s.  Sinus. 

Glycimeris  siliqua.     CHEMNITZ. 

Fig.  20.  View  of  a  left  valve.  Page  25 

a.  Dorsal  margin. 

b.  Anterior  margin. 

c.  Posterior  margin. 

NOTE.  —  All  figures  on  Plate  I.  are  copied  from  "A  Manual  of  the  Mollusca. 
A  Treatise  on  Recent  and  Fossil  Shells.  By  Dr.  S.  P.  Woodward,  A.  L.  S.,  F. 
G.  S.,  Second  Edition.  Lockwood  and  Co.,  London,  England,  1871." 


PLATE  II. 

Paracyclas  elliptica. 

Fig.  1-3.  Right,  left  and  cardinal  view  of  specimen.  Page  209 

Paracyclas  lirata. 

Fig.  4.  Left  view  of  a  specimen.  Page  211 

Fig.  5-7.  Left,  right  and  cardinal  view  of  specimen. 

Paracyclas  elongata. 

Fig.  8.  Left  view  of  a  specimen.  Page  210 

Modiomorpha  concentrica. 

Fig.  9,  10,  14.  Left  view  of   specimen,  showing  variations  in  size  and 

ornamentation.  Page  219 

Fig.  11.  12.  Right  and  profile  view  of  specimen. 

Crania  bordeni. 

Fig.  14.  View  of  two  specimens  adhering  to  left  valve  of  Modiomorpha 

concentrica.  Page  32 

Ptychodesma  knappianum. 

Fig.  13.  Profile  view  of  a  specimen.  Page  201 

Fig.  15.  Left  view  of  a  specimen. 

Fig.  16.  Left  view  of  a  smaller  individual. 

Fig.  17.  Right  view  of  a  specimen,  showing  striated  ligamental  area. 

Fig.  18.  View  of  left  valve  enlarged,  showing  striated  ligamental  area. 


PALAEONTOLOGY  OF  KENTUCKY" 


PLATE  II. 


15 

"... 


LOUISVILLE   LITH.CO 


PALAEONTOLOGY  OF  KENTUCKY. 


LOUISVILLE    LITH.CO. 


PLATE  III. 

Aviculopecten  pecteniformis. 

Fig.  1.  View  of  a  left  valve.  Page  225 

Actinopteria  boydi. 

Fig.  2.  View  of  a  left  valve,  showing  surface  ornamentation.  Page  229 

Discina  grandis. 

Fig.  3.  Dorsal  view  of  a  specimen.  Page  33 

Aviculopecten  fasciculatus. 

Fig.  4.  View  of  a  left  valve.  Page  224 

Glyptodesma  occidentale. 

Fig.  5.  View  of  a  left  valve.  Page  228 

Limoptera  cancellata. 
Fig.  6-8.  Left,  right  and  cardinal  view  of  specimen.  Page  198 


PLATE  IV, 

Cliiiopistha  striata. 
Fig.  1,  2.  Right  and  left  view  of  specimen  Page  200 

Cypricardinia  cataracta. 

Fig.  3.  Left  view  of  a  specimen.  Page  204 

Yoldia  ?  valvulus. 

Fig.  4,  5.  Left  view  of  two  specimens.  Page  223 

Cliiiopistha  subnasuta. 
Fig.  6-8,  12.  Left,  cardinal,  right  and  posterior  view  of  specimen.          Page  199 

Cliiiopistha  antiqua. 
Fig.  9-11.   Right,  cardinal  and  left  view  of  specimen.  Page  200 

Cypricardinia  cylindrica. 

Fig.  13-15.  Left,  cardinal  and  right  view  of  specimen.  Page  205 

Grammysia  gibbosa. 

Fig.  16,  19,  20.  Cardinal,  left  and  posterior  view  of  specimen.  Page  208 

Fig.  17.  Right  view  of  a  specimen. 

Fig.  18.  Right  view  of  a  smaller  specimen. 

Goniophora  truncata. 

Fig.  21-23.  Posterior,  side  and  cardinal  view  of  a  specimen.  Page  214 

Limoptera  cancellata. 

Fig.  24.  View  of  a  young  individual.  Page  198 


PALEONTOLOGY  OF  KENTUCKY. 


PLATE    IV. 


7 

"--., 


LOUISVILLE   LITH.   CO. 


PALEONTOLOGY  OF  KENTUCKY. 


PLATE   Y. 


. 


LOUISVILLE  LITH.  CO. 


PLATE  V. 

Glyptodesma  cancellata. 

Fig.  1.  View  of  a  left  valve.  Page  227 

Nucula  niotica. 
Fig.  2-4.  Anterior,  left  and  cardinal  view  of  a  specimen.  Page  222 

Nucula  neda. 

Fig.  5,  6.  Right  and  anterior  view  of  a  specimen.  Page  222 

Modiomorpha  charlestowiiensis. 

Fig.  7.  Right  view  of  a  specimen.  Page  218 

Fig.  8,  9.  Profile  view  of  two  specimens. 

Conocardium  cuneus. 

Fig.  10,  11.  Dorsal  and  ventral  view  of  a  specimen.  Page  203 

Fig.  12,  13,  15.  Ventral  views  of  three  specimens,  showing  variations 

in  size  and  ornamentation. 
Fig.  14.  Lateral  view,  showing  shield. 
Fig.  16.  Ventral  view  of  a  young  specimen. 
Fig.  17.  Dorsal  view  of  a  young,  very  perfect  specimen. 
Fig.  18.  Side  view  of  a  young  specimen. 
Fig.  19.  Enlargement  of  a  fragment  of  test,  showing  ornamentation. 

Faracyclas  ohioensis 
Fig.  20.  Right  view  of  an  average  size  specimen.  Page  213 


PLATE  VI. 


Spirifera  euruteines. 

Fig.  1-7,  9,  11-17.  A  series  of  specimens  showing  principal  varieties  of 

form.  Page  115 

Fig.  21,  22.  View  of  two  specimens  broken  so  as  to  show  the  spiral 
cones. 


Spirifera  euruteines,  var.  fornacula. 

Fig.  8,  10.  Cardinal  and  ventral  view  of  a  large  specimen.  Page  117 

Fig.  18,  19,  20.  Dorsal,  ventral  and  profile  view  of  a  small  specimen. 


PALEONTOLOGY  OF  KENTUCKY. 


PLATE  VI 


LOUISVILLE    LITH    CO. 


FAL/E  ONTOLOGY  OF  KENTUCKY. 


PLATE  VII 


DEL.ANO   \.\tf.  ft  CHAS.  STARCH. 


LOUISVILLE    LITH. 


PLATE   VII. 


Spirifera  oweni. 

Fig.  1-4,  7.  Dorsal,  profile,  cardinal,  ventral  and  front  view  of  speci- 
men. Page  126 

Fig.  5,  6.  Lateral  and  dorsal  view  of  a  young  specimen. 

Fig.  8,  9,  10.  View  of  three  specimens  broken  so  as  to  show  the 
spiral  cones. 


Spirifera  conradana. 

Fig.  11,  12.  Dorsal  and  ventral  view  of  a  specimen.  Page  110 

Fig.  13.  Dorsal  view  of  a  small  specimen. 


Spirifera  knappiana. 

Fig.  14.  Ventral  view  of  a  specimen.  Page  122 


PLATE    VIII. 


Spirifera  acuminata. 

Fig.  1.  Dorsal,  ventral,  profile,  front  and  cardinal  view  of  a  speci- 
men. Page  105 
Fig.  6,  7,  8.  Cardinal,  ventral  and  dorsal  view  of  an  internal  cast. 


Spirifera  gregaria. 

Fig.  9-13.  Ventral,  dorsal,  front,  profile  and  cardinal  view  of  a  speci- 
men. Page  119 


PALEONTOLOGY  OF  KENTUCKY". 


PLATE  VIII 


DEL. AND  LITH.  tY  CHAS.  STARCH. 


LOUISVILLE    LITH.  CO. 


PAUEONTOLOGY  OF  KENTUCKY. 


PLATE  IX 


Ml.  AND    MTH.BYCHAS.  STARCH. 


LOUISVILLE   LITH.  CO. 


PLATE  IX. 


Spirifera  atwaterana. 

Fig.  1-5.  Dorsal,  ventral,  front,  cardinal  and  profile  view  of  a  speci- 
men. Page  107 
Fig.  6,  7.  Dorsal  and  ventral  view  of  a  smaller  specimen. 


Spirifera  grieri. 

Fig.  8-12.  Cardinal,  front,  dorsal,  profile  and  ventral  view  of  a  speci- 
men. Page  120 
Fig.  13,  14.  Dorsal  and  profile  view  of  a  small  specimen. 


PLATE  X, 


Spirifera  byrnesi. 

Fig.  1-5.  Dorsal,  ventral,  front,  cardinal  and  profile  view  of  a  speci- 
men. Page  109 

Fig.  31-34,  36-39.  A  series  of  specimens,  showing  variety  in  form  and 
ornamentation. 


Spirifera  gregaria. 

Fig.  6-10.  Dorsal,  ventral,  front,  cardinal  and  profile  view  of  a  speci- 
men. Page  119 


Spirifera  varicosa. 

Fig.  11-20,  23-25.  A  series  of  specimens  showing  variety  in  size,  form 

and  ornamentation.  Page  134 


Spirifera  hobbsi. 

Fig.  21,  22.  Dorsal  and  ventral  view  of  a  specimen.  Page  121 

Fig.  26-30.  Dorsal,  ventral,  front,  cardinal  and  lateral  view  of  speci- 
men. 

Fig.  35,  40.  Dorsal  and  ventral  view  of  a  specimen,  showing  extreme 
extension  of  hinge-line. 


PALEONTOLOGY  OF  KENTUCKY.   ' 


PLATE  X. 


LOUISVILLE  LITH.  CO. 


PALEONTOLOGY  OF  KENTUCKY. 


UTH.  BY  CHAS.  ST*RCK. 


LOUISVILLE    LITH.  CO. 


PLATE  XI. 


Spirifera  mcconathii. 

Fig.  1-6.  Ventral,  cardinal,  dorsal,  front  and  Drotile  view  of  a  speci- 
men. Page  123 


Spirifera  divaricata. 

Fig.  6-10.  Dorsal,  front,  cardinal,  ventral  and  profile  view  of  a  speci- 
men. Page  113 
Fig.  11.  An  enlargement  of  a  portion  of  the  test  of  a  specimen. 


PLATE  XII. 

Spirifera  davisi. 
Fig.  1-4.  Dorsal,  front,  ventral  and  profile  view  of  a  specimen.  Page  112 

Spirifera  divaricata. 

Fig.  5-11.  A  series  of  specimens  showing  variations  in  form  and  size.     Page  113 

Spirifera  duodenaria. 

Fig.  12,  13,  16.  Ventral,  dorsal  and  profile  view  of  a  specimen.  Page  114 

Spirifera  arctisegmenta. 

Fig.  14,  15.  Ventral  and  dorsal  view  of  a  specimen.  Page  108 


PALEONTOLOGY  OF  KENTUCKY 


PLATE  XII 


OEL.UND  LITH.8Y  CHAS    STAOCK 


IOUISVILIE   IITH.  CO. 


PALEONTOLOGY   OF  KENTUCKY. 


PLATE  XIIL. 


LOUISVILLE    LITH.   CO. 


PLATE  XIII. 


Rhynchonella  tethys. 

Fig.  25-33.  A  series  of  specimens  showing  variations  in  size  and  num- 
ber of  plications.  Page  83 


Spirifera  segmenta. 

Fig.  36-38.  Dorsal,  ventral  and  profile  view  of  specimen.  Page  132 

Ryiichonella  Carolina* 
Fig.  1-3,  34,  35.  A  series  of  specimens  showing  variations  in  size.  Page  75 

Gyrtina  hamiltoniae. 

Fig.  4-12.  A  series  of  specimens  showing  variations  in  size  and  orna- 
mentation. Page  90 

Cyrtina  hamiltoniae,  var.  recta. 

Fig.  13.  View  of  a  small  dorsal  valve.  Page  97 

Fig.  14.  Ventral  view  of  a  specimen. 
Fig.  15.  Profile  view  of  a  specimen. 
Fig.  16.  View  of  a  larger  dorsal  valve. 

Fentamerella  arata. 

Fig.  17-20.  Dorsal,  ventral,  front  and  profile  view  of  a  specimen.  Page  49 

Cyrtina  crassa. 
Fig.  21-24.  Ventral,  cardinal,  profile  and  dorsal  view  of  a  specimen.        Page  95 


PLATE  XIV. 


Atrypa  aspera. 

Fig.  1-5,  7-11.  A  series  of  specimens  showing  variations  in  form  and 

size.  Page 

Fig.  6.  Interior  of  a  ventral  valve. 


Atrypa  reticularis. 

Fig.  12-17,  19.  A  series  of  specimens  showing  variations  in  form  and 

size.  Page  91 

Fig.  18.  Dorsal  view  of  a  specimen,  broken  so  as  to  show  spiral  cones. 
Fig.  20.   Ventral  view  of  a  specimen,  broken  so  as  to  show  spiral  cones. 
Fig.  21.  Side  view  of  a  specimen,  broken  so  as  to  show  spiral  cones. 
Fig.  22.  View  of  a  single  spiral  cone. 
Fig.  23.  View  of  interior  of  a  ventral  valve. 


PALE  ONTOLOGY  OF  KENTUCKY: 


m 


.  : : 


15 


OtL.  AND    LITH.  BY  CHA9.  3TA  R  _ 


LOUISVlUt  LITH.  CO 


PAUSONTOLOGYDF  KENTUCKY. 


PLATE  XV. 


-•'   .    - 


PLATE  XV. 

Atrypa  reticularis. 

Fig.  1.  Ventral  view  of  a  very  rugose  specimen.  Page  91 

Meristella  iiasuta. 


Fig.  2-5.  Cardinal,  dorsal,  profile  and  ventral  view  of  specimen.  Page 

Fig.  6-8.  Cardinal,  ventral  and  dorsal  view  of  an  interior  cast. 


Meristella  unisulcata. 
Fig.  9-16.  A  series  of  specimens  showing  variations  in  size  and  form.      Page  99 


PLATE  XVI. 

Orthis  propinqua. 
Pig.  1-3,  7-11.  A  series  of  specimens  showing  variations  in  size.  Page  43 

Orthis  vanuxemi. 

Fig.  4-6,  12,  12a-14.  A  series  of  specimens  showing  variation  in  size.         Page  45 

Trematospira  hirsuta. 

Fig.  15-19.  Profile,  dorsal,  ventral,  front  and  cardinal  view  of  speci- 
men. Page  136 

Terebratula  roemingeri. 

Fig.  20-22.  Profile,  ventral  and  dorsal  view  of  a  specimen.  Page  155 

Orthis  livia. 

Fig,  23,  24.  Dorsal  and  ventral  view  of  a  specimen.  Page  40 

Athyris  vittata. 

Fig.  25-29,  31,  32.  A  series  of  specimens  showing  variations  in  size 

and  ornamentation.  Page  87 

Fig.  30.  Ventral  valve  broken  to  show  position  of  spiral  cones. 


PALAEONTOLOGY  OF  KENTUCKY. 


PLATE  XVI 


DEL.  8.    LITH.BY    CHAS.     STARCK. 


LOUISVILLE    LITHOCR.CO. 


PALEONTOLOGY  OF  KENTUCKY 


PLATE   XVII. 


14 


DEL   »  LITH.BY  CHAS    STARCK 


LOUISVILLE  LITHOGRAPHING  CO. 


PLATE  XVII. 

Terebratula  harmonia 
Pig.  1-4.  Profile,  dorsal,  front  and  ventral  view  of  a  specimen.  Page  154 

Productella  subaculeata,  var.  cataracta. 

Fig.  5-8.  Dorsal,  ventral  and  front  and  transverse  view  of  a  speci- 
men. Page  69 
Fig.  9.  Ventral  view  of  a  specimen,  showing  almost  perfect  spines. 

Strophodonta  inequistriata. 

Fig.  10.   Ventral  valve  of  a  specimen.  Page  145 

Fig.  11.  An  enlargement  of  a  portion  of  the  surface,  showing  inter- 
calated striae. 

Bellerophon  leda. 

Fig.  12.  13.  Profile  and  side  view  of  a  specimen.  Page  158 

Tropidoleptus  carinatus. 

Fig.  14,  15.  Dorsal  and  ventral  view  of  a  specimen.  Page  46 

Chonetes  yandelliana. 

Fig.  16-18.  Ventral  and  dorsal  view  and  transverse  section  of  speci- 
men. Page  68 
Fig.  19.  Dorsal  view  of  a  larger  specimen. 

Strophodonta  profunda. 

Fig.  20.  Ventral  valve  of  a  specimen.  Page  148 

Fig.  21.  An  enlargement  of  a  portion  of  the  surface  showing  radiat- 
ing striae. 


Terebratula  lincklaeni. 

Fig.  22-24.  Ventral,  dorsal  and  profile  views  of  a  specimen.  Page  155 

Ambocoelia  umbonata. 

Fig.  25,  26.  Dorsal  and  profile  view  of  a  specimen.  Page  86 

Rhynchonella  tenuistriata. 

Fig.  27,  28,  29.  Ventral,  dorsal  and  front  view  of  a  specimen.  Page  82 

Orthis  goodwini. 

Fig.  30-32.  Dorsal,  ventral  and  profile  view  of  a  specimen.  Page  39 

Orthis  livia. 
Fig.  33-35.   Ventral,  dorsal  and  profile  view  of  a  specimen.  Page  40 

Spirifera  crispa,  var.  simplex. 

Fig.  36,  37.  Dorsal  and  ventral  view  of  a  specimen.  Page  111 

Spirifera  raricosta. 

Fig.  38-42.  Profile,  front,  cardinal,  ventral  and  dorsal  view  of  a  spe- 
cimen. Page  128 


PALEONTOLOGY  OF  KENTUCKY 


PLATE  XVIII 


rt  AND  LITH.1V 


PLATE  XVIII. 

Strophomena  rhomboidalis. 
Fig.  1-3.  Ventral,  dorsal  and  profile  view  of  a  specimen.  Page  150 

Strophodonta  hemispherica. 

Fig.  4-6.  Ventral,  dorsal  and  lateral  view  of  specimen.  Page  144 

Fig.  7-9.  Dorsal,  ventral  and  lateral  view  of  an  internal  cast. 

Strophodonta  demissa. 

Fig.  10-15.  A  series  of  specimen  showing  variations  in  size.  Page  143 

Fig.  16.  Lateral  view  of  a  specimen. 

Strophodonta  perplana. 

Fig.  17.  Ventral  view  of  a  specimen.  Page  147 

Ghonetes  acutiradiata. 

Fig.  18-20.  Ventral,  dorsal  and  profile  view  of  a  specimen.  Page  66 


PLATE  XIX. 


Turbo  shumardi. 

Fig.  1.  Apertural  view  of  a  specimen.  Page  191 

Fig.  2.  Dorsal  view  of  a  specimen. 

Fig.  3.  Vertical  view  of  a  specimen. 

Fig.  4.  Vertical  view  of  a  larger  specimen. 


Platyostoma  lineata. 

Fig.  5.  Vertical  view  of  a  specimen.  Page  183 

Fig.  6.  An  enlargement  of  a  portion  of  the  test. 
Fig.  7.  Apertural  view  of  a  specimen. 
Fig.  8.  Dorsal  view  of  a -specimen. 


PALEONTOLOGY  OF  KENTUCKY. 


PLATE  XIX. 


LOUISVILLE    LITH   TO 


PALAEONTOLOGY  OF  KENTUCKY. 


PLATE  XX. 


OEI.AN3    UTK    ft?    TO 


LOUISVILLE    LITH.  CO. 


PLATE  XX 

Polyphemopsis  lo  uisvillae. 

Fig.  16-19.  A  series  of  specimen  showing  variations  in  size.  Page  180 

Macrocheilus  carinatus. 

Fig.  20-23.  A  series  of  specimen  showing  variations  in  size.  Page  180 

Trochonema  rectilatera. 

Fig.  1,  2.  Apertural  and  dorsal  view  of  a  specimen.  Page  189 

Trochonema  yandellana. 

Fig.  3.  Apertural  view  of  a  specimen.  Page  190 

• 

Calloncma  bellatula. 

Fig.  4-7.  A  series  of  specimen  showing  variations  in  size  and  orna- 
mentation. Page  175 

Loxonema  hydraulicum. 
Fig.  8,  9.  View  of  three  specimen  enclosed  in  matrix.  Page  178 

Cyclonema  cancellata. 
Fig.  10,  11.  Dorsal  and  apertural  view  of  a  specimen.  Page  187 

Callonema  imitator. 
Fig.  12,  13.  Vertical  and  apertural  view  of  a  specimen.  Page  176 

Goniatites  discoideus. 
Fig.  14,  15.  Basal  and  profile  view  of  a  specimen.  Page  194 


PLATE  XXI. 


Euomphalus  decewi. 
Fig.  1,  2.  Profile  and  upper  surface  view  of  a  specimen.  Page  181 

Euomphalus  sampsoni. 

Fig.  3,  4.  Profile  and  lateral  view  of  a  specimen.  Page  182 

Platyostoma  turbinata. 

Fig.  6,  6.  Dorsal  and  vertical  view  of  a  specimen.  Page  184 

Platyostoma  lineata. 

Fig.  7,  8.  Vertical  and  dorsal  view  of  a  specimen.  Page  183 

Pleurotomaria  procteri. 


Fig.  9,  10.  Dorsal  and  vertical  view  of  a  specimen.  Page  173 

Fig.  13.  Dorsal  view  of  a  small  specimen. 


Pleurotomaria  sulcomarginata.  • 

Fig.  11,  12.  Vertical  and  dorsal  view  of  a  specimen.  Page  174 


PAL-EONTOLOGY  OF  KENTUCKY 


PLATE    XXI. 


DEL.  a,  tITH.  8Y  CHAS.   STARCK. 


IOUISVIUE   LITHOGRAPHING  CO. 


Platyostoma  lineata,  var.  callosa. 
Fig.  14.  Lateral  view  of  a  specimen.  Page  184 

Gomphoceras  turbiniforme. 

Fig.  15,  16.   View  of  two  specimens  showing  variation  in  size.  Page  194 

Gomphoceras  oviforme. 

Fig.  17.  Side  view  of  a  specimen.  Page  193 

Fig.  18.  View  of  the  aperture  of  a  specimen. 


PLATE  XXII. 


Turbo  shumardi. 

Fig.  1.  Dorsal  view  of  an  internal  cast  of  a  specimen.  Page  191 

Fig.  2.  Dorsal  view  of  a  perfect  specimen,  very  large. 


Bucania  devonica. 

Fig.  3,  4.  Vertical  and  front  view  of  a  specimen  Page  160 

Cyclonema  multilira. 
Fig.  5.  View  of  a  gutta  percha  cast.  Page  188 

Strophostylus  varians. 

Fig.  6,  7.  Dorsal  and  vertical  view  of  a  specimen.  Page  186 

Loxonema  laeviusculum 

Fig.  8.  View  of  a  somewhat  distorted  specimen.  Page  178 

Fig.  9.  View  of  a  more  perfect  specimen. 

Platyostoma  lineata  var.  callosa. 
Fig.  10,  11.  Side  and  summit  view  of  a  specimen.  Page  184 


PALEONTOLOGY  OF  KENTUCKY. 


PLATE  XXIL 


;"L.8.    LITH.BY    CHAS.   STARCH. 


LOUISVILLE   LITHOGRAPHING    CO. 


PALEONTOLOGY  Of  KENTUCKY. 


PLATE  XXIII. 


v  * 


pv 


le 


DEL.  &  LITH.  BY    CHAS.    STARCK 


LOUISVILLE    LITHOGRAPHING   CO. 


PLATE  XXIII. 


Platyceras  dumosum. 

Fig.  1-4.  A  series  of  specimen  showing  variations  in  size,  distribu- 
tion and  condition  of  spines.  Page  162 
Fig.  5,  6.  View  of  two  specimen  exfoliated,  and  showing  spine  bases. 
Fig.  12.  Vertical  view  of  a  young  specimen. 


Platyceras  dumosum,  var.  rarispinum. 

Fig.  7,  8.  Dorsal  and  lateral  view  of  a  specimen.  Page  163 

Platyceras  bucculentunu 

Fig.  9,  11.  Lateral  view  of  two  specimen,  showing  variation  in  size.      Page  160 

Platyceras  symmetricum. 
Fig.  10.  Lateral  view  of  a  specimen.  Page  167 


PLATE  XXIV. 

Nautilus  maximus* 
Fig.  1.  Side  view  of  a  specimen.  Page  196 

Callonema  clarki. 

• 

Fig.  2.  Summit  view  of  a  specimen.  Page  175 

Fig.  3.  Side  view  of  a  specimen. 
Fig.  4.  Apertural  view  of  a  specimen. 
Fig.  5.  Side  view  of  a  smaller  specimen. 


PALEONTOLOGY  OF  KENTUCKY 


PLATE  XXIV. 


DEL.&  UTH.BYCHAS.  STARCK 


LOU1SVHJ.K  LITHOGRAPHING  CO. 


PALEONTOLOGY  OF  KENTUCKY. 


PLATE    XXV. 


DEL.&  LITH   SY    CHAS.   STARCK. 


LOUISVILLE    LITHOGRAPHING     CO. 


PLATE  XXV. 

Platyceras  milleri. 

Fig.  1.  Anterior  view  of  a  specimen.  Page  165 

Platyceras  conicum. 

Fig.  2,  11.  Dorsal  view  of  two  specimen,  showing  variation  in  size.  Page  161 

Platyceras  bucculentum. 

« 

Fig.  3.  Anterior  view  of  a  specimen.  Page  160 

Platyceras  multispinosum. 

Fig.  4.  View  of  a  cast  of  a  very  large  specimen.  Page  166 

Platyostoma  lineata,  var.  callosa. 

Fig.  5-7.  Apertural,  side  and  dorsal  view  of  a  specimen.  Page  184 

Platyceras  compressum. 

Fig.  8,  9.  Dorsal  and  posterior  view  of  a  specimen.  Page  162 

Platyceras  ventricosum. 

Fig.  6.  Anterior  view  of  a  specimen.  Page  168 


PLATE  XXVI. 


Lingula  triangulata. 
Fig.  1.  Ventral  view  of  a  specimen.  Page  34 

Spirifera  medialis. 

Fig.  2-5.  Cardinal,  ventral,  dorsal  and  profile  view  of  a  specimen.       Page  125 

Rhynchonella  acinus. 

Fig.  6,  13,  14.  Dorsal,  profile  and  front  view  of  a  specimen.  Page  73 

Froductella  semiglobosa. 
Fig.  7.  Ventral  view  of  a  specimen.  Page  70 

Murchisonia  desiderata. 

Fig.  8.  View  of  an  internal  cast  of  a  specimen,  which  is  entirely  cov- 
ered by  an  incrusting  coral,  studded  with  somewhat  irregularly 
distributed  tubercles.  Page  169 

Bucania  devonica. 

Fig.  9.  View  of  an  internal  cast.  Page  160 

Modiomorpha  alta. 

Fig.  10.  Left  view  of  a  specimen.  Page  217 

Pleurotomaria  casii. 

Fig.  11.  Dorsal  view  of  a  specimen.  Page  171 

Pleurotomaria  arabella. 

Fig.  12.  Apertural  view  of  an  internal  cast  retaining  a  small  portion 

of  the  test.  Page  171 


PALEONTOLOGY  OF  KENTUCKY. 


PLATE  XXVI 


Dtl.   &LITH.BY    CHAS.3TARCK. 


lOUISVIllE    LITHOGRAPHING   C.O. 


PALEONTOLOGfTOF  KENTUCKY. 


PLATE  XXVII. 


m 

'.v-.*'- 


-••: 


28 


DCL.ANO    UTH.   »Y    CHAS.    STARCH 


LOUISVILLE   LITH.CO. 


PLATE  XXVII. 

Orthis  rugaeplicata. 
Fig.  1-3.  Dorsa*,  profile  and  ventral  view  of  a  specimen.  Page  44 

Orthis  nisis. 

Fig.  4,  5.  Ventral  and  profile  view  of  a  specimen.  Page  42 

Cyrtia  exporrecta. 

Fig.  6,  7,  8,  20.  Dorsal,  front,  cardinal  and  profile  view  of  specimen.      Page  93 

Rhynchonella  stricklandi. 

Fig.  9-11.  Dorsal,  profile  and  ventral  view  of  a  specimen.  Page  81 

Fentamerus  littoni. 

Fig.  12,  13.  Dorsal  and  profile  view  of  a  specimen.  Page  58 

Pentamerus  complanatus. 

Fig.  14.  Cardinal  view  of  a  specimen.  Page  53 

Fig.  15,  16.  Dorsal  view  of  two  specimen,  showing  variations  in  size. 

Spirifera  rostellum. 

Fig.  17-19.  Dorsal,  ventral  and  front  view  of  a  specimen.  Page  129 


Cyrtia  exporreeta,  var.  arrecta. 

Fig.  21.  Profile  view  of  a  specimen.  Page  94 

Rhynchonella  saffordi. 

Fig.  22-24.  Dorsal,  front  and  profile  view  of  a  specimen.  Page  79 

Fentamerus  nucleus. 

Fig.  25-27.  Front,  profile  and  dorsal  view  of  a  specimen.  Page  59 

Fig.  28.  An  enlargement  of  a  portion  of  surface  of  test. 


PALEONTOLOGY  OF  KENTUCKY. 


PLATE   XXVIIi. 


PLATE  XXVIII. 

Fentamerus  knappi. 

Pig.  1-4.  Dorsal,  ventral,  profile  and  cardinal  view  of  a  specimen.         Page  55 

Fentamerus  nysius,  var.  crass  icostus. 

Fig.  5-8.  Profile,  cardinal,  dorsal  and  ventral  view  of  a  specimen.         Page  60 


PLATE  XXIX. 

Pentamerus  knighti. 

Fig.  1,  2.  Dorsal  and  profile  view  of  a  specimen.  Page  57 

Fig.  17.  Profile  vie\v  of  an  unusually  large  specimen. 

Rhynchonella  stricklandi. 
Fig.  3-6.  Dor»al,  cardinal,  profile  and  front  view  of  a  specimen.  Page  81 

Meristina  maria. 
Fig.  7-10.  Dorsal,  ventral,  profile  and  front  view  of  a  specimen.          Page  101 

Streptorhynchus  subplanus. 

Fig.  11,  12.  Profile  and  ventral  view  of  a  specimen.  Page  141 

Spirifera  radiata. 

Fig.  13-16.  Dorsal,  ventral,  profile  and  cardinal  view  of  a  specimen.  Page  130 

Orthis  biforata. 

Fig.  18-22.  Ventral,  profile,  dorsal,  front   and   cardinal  view  of  a 

specimen  Page  35 

Pentamerus  pergibbosus. 
Fig.  23,  24.  Profile  and  dorsal  view  of  a  specimen.  Page  62 

Spirifera  rostellum. 
Fig.  25.  Dorsal  view  of  a  specimen.  Page  129 

Strophodonta  profunda. 

Fig.  26.  Ventral  view  of  a  specimen.  Page  148 


PALEONTOLOGY  OF  KENTUCKY 


PLATE  XXIX 


m 


•  \^~ 


r 


DEL.&UTH.Br  CHAS.   STARCH. 


PALEONTOLOGY  OF  KENTUCKY 


PLATE   XXX. 


DEL.&  LITH  BY  CHAS.  STARCK 


LOUISVILLE  LITHOCHAPHING  CO. 


PLATE  XXX. 

r> 

Lituites  marshL 
Fig.  1.  Anterior  view  of  a  specimen.  Page  195 

Pentamerus  oblongus,  var.  cylindricus 

Fig.  2-4.  Profile,  dorsal  and  ventral  view  of  a  specimen.  Page  61 


PLATE  XXXI. 

Rhynchonella  louisvillensis. 
Fig.  1-4.  Dorsal,  ventral,  front  and  profile  view  of  a  specimen.  Page  77 

Murchisonia  petilla. 

Fig.  5.  View  of  an  internal  cast.  Page  170 

Rhynchonella  gainesi. 

Fig.  6,  7.  Dorsal  view  of  two  specimens.  Page  76 

Fig.  8,  9.  Front  and  ventral  view  of  a  specimen. 

Spirifera  mucronata. 

Fig.  10,  11.  Ventral  and  dorsal  view  of  a  specimen.  Page  126 

Tentaculites  scalariformis. 
Fig.  12.  View  of  a  specimen,  enlarged  xi.  Page  156 

Spirifera  sculptilis. 

Fig.  13.  Ventral  view  of  a  valve.  Page  132 

Centronella  glans-fagea. 
Fig.  14-17.  Front,  pronies  dorsal  and  ventral  view  of  a  specimen.  153 


PALEONTOLOGY  OF  KENTUCKY. 


PLATE  XXXI, 


DEL  &LITH   BY   CHAS.  STARCH 


Faracyclas  octerlonii. 
Fig.  18.  Left  view  of  a  specimen.  Page  212 

Chonetes  yandelliana. 

Fig.  19,  20.  Ventral  and  profile  view  of  a  specimen.  Page  68 

Fig.  30.  Transverse  section  of  a  specimen. 

Platyceras  echinatum. 

Fig.  21.  Side  view  of  a  specimen.  Page  164 

f 

Rhynchonella  tethys. 
Fig.  22-25.  Dorsal,  profile,  front  and  ventral  view  of  a  specimen.  Page  83 

Pentamerella  thusnelda. 

Fig.  26-28.  Profile,  dorsal  and  ventral  view  of  a  specimen.  Page  51 

Loxonema  hamiltoniae. 

Fig.  29.  View  of  a  rather  perfect  specimen.  Page  177 

Streptorhynchus  arctostriata 
Fig.  31-33.  Cardinal,  ventral  and  dorsal  view  of  a  specimen.  Page  140 


PLATE  XXXII. 

Nucleospira  concinna. 
Fig.  1-4.  Dorsal,  ventral,  front  and  profile  view  of  a  specimen.  Page  103 

Atrypa  reticularis,  var.  niagarensis. 

Fig.  5-8.  Profile,  dorsal,  front  and  ventral  view  of  a  specimen.  Page  92 

Fig.  44-47.  Dorsal,  ventral,  profile  and  front  view  of  a  specimen,  show- 
ing variation  in  size. 

Pentamerus  knotti. 

•  . 
Fig.  9-12.  Dorsal,  profile,  ventral  and  front  view  of  specimen.  Page  5 

Rhynchonella  acinus. 

Fig.  13-16.  Dorsal,  ventral,  profile  and  front  view  of  a  specimen.  Page  73 

Anastrophia  internascens. 
Fig.  17-20.  Dorsal,  ventral,  front  and  profile  view  of  a  specimen.  Page  47 

Leptocoelia  hemispherica. 

Fig.  21-23.  Dorsal,  ventral  and  profile  view  of  a  specimen.  Page  152 

Fig.  36-39.  Profile,  front,  ventral  and  dorsal  view  of  a  larger  speci- 
men. 

Rhynchonella  pisa. 

Fig.  24-27,  Profile,  dorsal,  ventral  and  front  view  of  a  specimen.  Page  78 


PALEONTOLOGY  OF  KENTUCKY. 


PLATE  XXXII. 


DEL.&tlTH.Br  CHAS   STARCK. 


LOUISVILLE  1ITHOGRAPHING  CO. 


Spirifera  foggi. 

Fig.  28-31.  Dorsal,  front,  ventral  and  profile  view  of  a  specimen.  Page  117 

Orthis  hybrida. 
Fig.  32-35.  Dorsal,  ventral,  front  and  profile  view  of  a  specimen.  Page  39 

Trematospira  helena. 
Fig.  40-43.  Dorsal,  ventral,  profile  and  front  view  of  a  specimen.  Page  137 

Rhynchonella  rugaecosta. 

Fig.  48-51.  Dorsal,  front,  ventral  and  profile  view  of  a  specimen ;  all 

enlarged  xi.  Page  78 

Orthis  elegantula. 

Fig.  52-57.  A  series  of  specimens  showing  variations  in  size.  Page  37 

Rhynchonella  cuneata,  var.  americana. 

Fig.  58,  59.  Dorsal  and  ventral  view  of  a  specimen.  Page  85 

Fig.  62,  63.  Front  and  profile  view  of  a  specimen. 

Cyrtia  exporrecta,  var.  arrecta. 

Fig.  60,  61.  Profile  and  cardinal  view  of  a  specimen.  Page  94 

Atrypa  calvini. 

Fig.  64-66.  Profile,  ventral  and  dorsal  view  of  a  specimen.  Page  89 


PLATE  XXXIII. 

Rhynchonella  saffordi,  var.  depressa. 
Fig.  1-3.  Dorsal,  ventral  and  profile  view  of  a  specimen.  Page  80 

Rhynchonella  saffordi. 

Fig.  4-6.  Profile,  dorsal  and  ventral  view  of  a  specimen.  Page  79 

Nucleospira  pisiformis. 

Fig.  7-9.  Profile,  dorsal  and  ventral  view  of  a  specimen.  Page  104 

Meristina  nitida. 

Fig.  10,  11.  Dorsal  and  profile  view  of  a  specimen.  Page  102 

Fentamerus  ventricosus. 

Fig.  12-14.  Dorsal,  profile  and  ventral  view  of  a  specimen.  Page  64 

• 

Fentamerus  oblongus. 

Fig.  15-17.  Dorsal,  profile  and  ventral  view  of  a  specimen.  Page  60 

Rhynchonella  indianensis. 

Fig.  18-20.  Dorsal,  ventral  and  profile  view  of  a  specimen.  Page  76 


PALEONTOLOGY  OP  KENTUCKY. 


PLATE    XXXIII, 


'JCL.A  I. 'TH.B1    r.HAS.  STARCK 


LOUISVIUE  LITHOGRAPHING  CO. 


Cyclonema  rugaeliiieata. 
Fig.  21.  Anterior  view  of  a  partly  exfoliated  specimen.  Page  187 

Strophodonta  demissa. 
Fig.  22.  Ventral  view  of  a  specimen.  Page  148 

Spirifera  dubia. 
Fig.  23,  24.  Dorsal  and  profile  view  of  a  specimen.  Page  115 

Fentamerus  uniplicatus. 

Fig.  25,  26.  Dorsal  view  of  a  specimen  Page  63 

Pentamerus  nucleus. 
Fig.  27-29,  31-33.  A  series  of  specimens  showing  variation  in  size.  Page  59 

Flatyostoma  niagarense. 
Fig.  30.  Vertical  view  of  a  young  specimen.  Page  185 


PLATE  XXXIV. 

Cypricardites  halli. 
Fig.  1-6.  A  series  of  specimens  showing  variation  in  size  and  form.        Page  206 

Orthis  linneyi. 
Fig.  7-13.  A  series  of  specimens  showing  variation  in  size  and  form.        Page  41 

Orthis  borealis. 

Fig.  14-20.  A  series  of  specimens  showing  variation  in  size  and  form.     Page  36 

Zygospira  kentuckiensis. 
Fig.  21-25.  A  series  of  specimens  showing  variation  in  size  and  form.    Page  138 

Rhynchonella  increbescens. 
Fig.  26-29.  Dorsal,  ventral,  front  and  profile  view  of  a  specimen.  Page  83 

Orthis  flabellum, 

Fig.  30.  Dorsal  view  of  a  specimen.  Page  38 

Stricklandinia  louisvillensis. 
Fig.  31-34.  Ventral,  dorsal,  profile  and  cardinal  view  of  a  specimen.        Page  65 

Cyrtia  exporrecta,  var.  arrecta. 

Fig.  35.  Cardinal  view  of  a  specimen.  Page  94 


PALEONTOLOGY  OP  KENTUCKY. 


PIRATE  XXXIV. 


PALEONTOLOGY  OF  KENTUCKY. 


PLAT;-      XXXV. 


DEL.&.   UTH    BY     CHAS.    STARCH. 


PLATE  XXXV. 


Ptilodictya  hilli. 

•> 

Fig.  1.  Transverse  section  of  a  specimen.  Page  30 

Fig.  2.  View  of  an  unusually  large  front. 
Fig.  4.  A  portion  of  a  frond  enlarged. 
Fig.  5..  View  of  a  small,  imperfect  frond. 


Brachiospongia  digitata. 

Fig.  3.  Basal  view  of  an  unusually  perfect  specimen.  Page  29 


PLATE  XXXVI. 


Brachiospongia  digitata. 


Fig.  1.  Front  view  of  the  specimen  figured  on  Plate  XXXV.  Page  29 

Fig.  2.  Summit  view  of  the  same. 


PALEONTOLOGY  OF  KENTUCKY. 


PLATE  XXXVI 


DF.l  «  L!  I  H.B1    CHAS.  STAKCK. 


[NOTE.— The  Monograph  on  Kentucky  Fossil  Sheila  was  published  after  the  death  of  Mr.  Nettelroth,  and 
was  thus  deprived  of  the  advantage  of  the  supervision  and  correction  of  proof  by  him.] 


IR,  IR,  .A.  T 


PAGE.          LINE. 

17  10  ReadEozoon. 

17  26  and  27  Read  R.  I.  Murchison. 

30  10  Read  Polyzoa. 

30  Under  PTILODICTYA  HILLI  add ;    Ptilodictya  Mill,   James. 

The  Palaeontologist,  page  4,  1878.  The  original  descrip- 
tion of  this  species  makes  it  unbranched  and  not  digi- 
tate. None  of  the  figured  specimens  show  any  indication 
of  branching. 

31  25  Read  H.  H.  Hill. 

32  Under  reference  to  27th  Regents  Report  add  ;  The  two  dif- 

ferent references  and  dates  given  here  arise  from  the  fact 
that  the  plates  illustrating  the  descriptions  published  in 
1872,  were  not  published  until  1875  when  the  27th  Report 
was  issued.  These  plates  are  numbered  "24th  Report," 
and  should  always  be  included  with  it,  though  not  pub- 
lished until  three  years  later. 

33  19  Read  p.  17. 

37  17  Read  vol.  II. 

38  7,  8,  9        Read  FLA BELL ULUM. 

39  3  From  bottom,  read  vol.  II. 

41  After  ORTHIS   LITSWEYI,  add    James,  not    n.  sp.  ;   also  add 

Orthis  (?)  Imneyl,  James.  The  Palaeontologist,  page  41, 
1881. 

42  8  From  bottom,  read  Hall  &  Whitfield. 

42  5  From  bottom,  read  figs.  4-8. 

43  17  Read  1867. 

44  6  Read  Hall  &  AVhitfield. 

45  14  Read  pp.  135,  136. 

46  Add  to  TROPIDOLEPTUS,  10th  Rept.  State  Cab.  Nat.  Hist., 

p.  151,  1857. 

47  After  line  6  from  bottom,  add,  Anci.slropliia  mternascens, 

Hall,  28th  Rept.  State  Cnb.  Nat.  Hist.,  p.  168,  1879. 


II  ERRATA. 

PAGE.         LINK. 

49  7  From  bottom,  read  1841. 

50  7  Prom  bottom,  read  1858. 
53        J2                  Read  tenuicosta. 

55        15  Read  Hall  &  Whitlield. 

58  18  Add  1859. 

59  1  Read  Hall  &  Whitiield. 

60  1  Read  Hall  &  Whitneld. 
60          3                  Read  p.  185,  1872. 

60  4  Read  4-7. 

60  25  Read  Hall  &  Whitlield. 

60  4  From  bottom,  read  Ibid      Idem. 

60  2  From  bottom,  add  1852. 

68  Make  line  13,  14  instead. 

71  21  Read  p.  168. 

71  22  Read  Atrypa  (OrtMs)  quadricostata. 

75  3  Read  pi.  54. 

83  3  From  bottom,  read  1847. 

83  5  From  bottom,  read  Ryiwlwnella  capax,   Conrad.,  and  add 

below;  Atrypa  capax,  Conrad.  Jour.  Phil.  Acad.  Sci., 
vol.  8,  p.  264,  1842.  Rhynclionella  increbescens,  Hall. 
12th  Report  State  Cab.  Nat.  Hist.,  p.  66,  1859.  13th 
Report  State  Cab.  Nat.  Hist.,  p.  66,  1861.  Rhynclio- 
nella  capax,  Billings.  Pal.  Foss.  Can.,  vol.  1,  p.  142, 
1862.  RhyncJionella  capax,  Meek.  Pal.  Ohio,  vol.  1, 
p.  123,  1873. 

84  25  Read  1876. 

85  3  Read  1876. 

85  Under  Ambocoelia  add;  Ambocoelia,   Hall.     13th    Rep.  N. 

Y.  State  Cab.  Nat,  Hist.,  p.  71,  1860. 
88  Add   between   line  8  and  9  from   bottom,   Atrypa  spinosa 

vel  aspera. 

93        11  From  bottom,  read  trapezoidalis. 

93        10  From  bottom,  read  trapezoidalis. 

103  10  From  bottom,  read  pp.  25,  26. 

104  7  From  bottom,  add  p.  221 . 

104  4  From  bottom,  read  pp.  301,  302. 

105  13  From  bottom,  add  1867. 

108        10  (Note. — This  reference  is  evidently  to  the  extra  or  author's 

edition  of  the  paper  published  in  the  1  Oth  Annual  Report, 
with  new  pagination.) 


ERRATA.  Ill 

PAGE.  LINE. 

110  5  Add  1867. 

112  3  From  bottom,  read  W.  J.  Davis. 

113  4  Read  'oetiustus. 
113  5  Add  1867. 

120        23  Read  27  and  28. 

124        23  Add  vol.  I,  part  2. 

126  Add  to  references  of  S.  oweni ;  Spirifer  oweni.  Hall.     10th 

Rep.  State  Cab.  Nat.  Hist.,  p.  129,  1859. 

128  5  Read  p.  132. 

129  11  Read  Hall  &  Whitneld. 

13  Read  1872. 

14  Read  1875. 
132          4  Read  1867. 

7  From  bottom,  add  p.  181, 

135  25  Add  1867. 

136  3  Read  p.  168. 

4  Read  14th  Report,  1861. 

138  Under  Zygospira  TcentucJdensis  add ;    Zygospira  modesta, 

var,   IcentucMensis,    James.      The    Palaeontologist,    p.    7, 

1878. 
143        15  Read  1857. 

16  Add  vol.  1,  part  2,  and  read  1858. 

145          6  From  bottom,  read  1867. 

147        15  Read  1857.     Add  to  references  StropJiodonta  perplana,  Hall. 

Pal.  New  York,  vol.  4,  pp.  92,  98-101,  1867. 
151          5  From  bottom,   after  Leptocoelia  add  Leptocoelia  concava, 

Hall.     JOth   Report,   Reg.   State  Cab.  Nat.  Hist.,  p.  107, 

1857.      Leptocoelia,    Hall,    12th    Rept.    State    Cab.    Nat. 

Hist.,  p.  32,  1859. 

156  4  From  bottom,  read  Tentaculities,  1879. 

157  5  From  bottom,  read  1879. 

158  6  From  bottom,  read  24th. 

159  Under  Bucania,  add  Pal.  of  New  York,  vol.  1,  p.  32. 
161        21  Read  1879. 

163          7  From  bottom,  read  1879. 

165  4  Read  p.  32. 
6  Read  1879. 

166  7  From  bottom,  read  1879. 

167  16  Read  1879. 

168  5  Read  1879. 


ERRATA. 


PAGE. 
168 


LINE. 

5 


170 

174 

8 

179 

9 

183 

23 

184 

12 

188 

9 

194 

12 

196 

13 

198 

12 

199 

203 

205 
209 

211 
224 
2-25 

229 

Plate 

Plate 

Plate 

Plate 


12 

4 
6 

5 

4 
19 

8 

4 

4 
19 
I. 

VIII. 
X. 
XIII. 


Plate  XXV. 
Plate  XXVI. 

Plate  XXXI. 
Plate  XXXII. 

Plate  XXXIV. 


Between  line  4  and  3  from  bottom  add  ;  Platyceras  ven- 
tricosum,  Hall.  12th  Kept.  State  Cab.  Nat.  Hist.,  p.  17, 
1859. 

For  petilla  read  petila. 

From  bottom,  add  p.  5<>,  1879. 

Read  p.  130. 

Read  1879. 

Add  part  2,  p.  23. 

From  bottom  for  pi.  12,  read  p.  36. 

From  bottom,  add  pi.  13,  as  var.  Ohioensis. 

Read  1879. 

Read  1884. 

After  Cliiiopistha  add  ;  Proc.  Phila.  Acad.  Nat.  Sci.,  p.  43, 
1870. 

From  bottom,  read  pi.  11. 

Read  pp.  171,  172. 

Read  1885. 

Place  (?)  after  Cypricardinia  in  references. 

From  bottom  add  ;  &  p.  95,  fig.  18,  1885. 

From  bottom,  add  1872. 

Add  1885. 

Read  1884. 

Read  1884. 

From  bottom,  add  pp.  1-4,  and  read  1884. 

Read  1884. 

Description,  transpose  figs.  7  and'9. 
Description,  for  fig.  1  read  fig.  1-5. 
For  32  in  lower  left  hand  corner  read  36. 
Change  23   on   second  line   of   figures   from   lower  left  hand 

corner  to  32. 

In  description  for  fig.  6,  last  line,  read  fig.  10. 
Add  13  to  upper,  and  14  to  lower  one  of  the  two  unnumbered 

figures. 

Read  Murchisonia  petila  for  M.  petilln. 
Fig.  12,  read  enlarged  twice. 
After  Rhyn.  knotti,  read  p.  56. 
Under  Rhyn.  rugaecosta,  read  enlarged  twice. 
For  Rhynchonella  cuneata,  etc.,  read  Rhynchotreta. 
For  Rhyn.  increbescens,  read  R.  capax. 
For  Orthis  flabellum,  read  O.  flabellulum. 


//. 


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